List of open-access journals

A list of open-access journals catalogues scholarly periodicals that make peer-reviewed research articles freely accessible online without subscription or paywall restrictions, typically funded through author article processing charges (APCs), institutional support, or sponsorships rather than reader fees.^[1][2] These publications adhere to open access principles, providing immediate availability of full-text content under permissive reuse licenses like Creative Commons, thereby facilitating broader dissemination, citation, and application of scientific and academic knowledge beyond paywalled traditional journals.^[3] Directories such as the Directory of Open Access Journals (DOAJ), established in 2003 as an independent index, curate and vet these journals to ensure compliance with quality standards including transparent peer review, editorial policies, and ethical practices, currently encompassing over 20,000 titles across diverse disciplines.^[4] The open access model gained momentum in the late 1990s with the advent of digital repositories and publishers like BioMed Central, culminating in foundational declarations like the 2002 Budapest Open Access Initiative, which advocated for gratis online availability and libre reuse rights to counteract escalating subscription costs and access barriers in scholarly communication.^[5] While open access has demonstrably increased research visibility and impact—evidenced by higher citation rates for OA articles compared to subscription-based counterparts—it has also spawned notable challenges, including the proliferation of predatory journals that exploit APC models by promising rapid publication with scant or fabricated peer review, thereby eroding trust in the ecosystem and inflating low-quality output amid academic publication pressures.^[6][7] Such lists and vetting services play a critical role in distinguishing legitimate outlets, as empirical analyses reveal that predatory operations often mimic reputable ones but fail basic transparency metrics, with thousands identified and delisted from indices over time.^[8] Despite these issues, rigorous open access journals contribute substantially to equitable knowledge sharing, particularly in under-resourced fields, underscoring the model's causal trade-offs between accessibility gains and vigilance against incentive misalignments in fee-based publishing.^[9]

Fundamentals of Open Access

Definition and Principles

Open access (OA) publishing constitutes a model in which scholarly outputs, particularly peer-reviewed journal articles, are disseminated online without financial, legal, or technical barriers to access beyond those inherent in internet connectivity. This approach ensures that research is immediately and permanently available to the global public, fostering unrestricted reading, downloading, copying, distribution, printing, searching, linking, and lawful reuse of the material.^[1][10] The foundational principles of OA were articulated in the Budapest Open Access Initiative (BOAI) of February 14, 2002, which defines OA as the net removal of all price and permission barriers that impede the circulation of scientific research, distinguishing between two primary strategies: self-archiving (green OA) and OA journals (gold OA). BOAI emphasizes that for OA journals, authors and publishers relinquish subscription-based revenue models in favor of alternative funding, such as institutional subsidies or article processing charges (APCs), while granting users broad permissions equivalent to fair use under copyright law. This initiative, endorsed by over 12,000 signatories as of 2022, prioritizes accelerating research progress by maximizing accessibility without compromising quality through rigorous peer review.^[10] Complementing BOAI, the Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities, adopted on October 22, 2003, by international research organizations, advocates for online availability of document types such as journal articles, monographs, and datasets, coupled with machine-readable licensing terms that permit productive reuse for educational, scientific, and scholarly purposes. Signatories, including over 600 institutions by 2023, commit to supporting OA infrastructures that ensure long-term preservation and interoperability, underscoring the causal link between unfettered access and enhanced knowledge creation. These principles collectively prioritize empirical dissemination over proprietary control, though implementation varies, with "gratis" OA focusing on free reading access and "libre" OA extending to derivative works under open licenses like Creative Commons Attribution.^[11][10]

Historical Development

The origins of open-access journals trace back to the advent of digital preprint repositories in the early 1990s, which challenged traditional subscription-based models by enabling free online dissemination of scholarly work. A pivotal early example was arXiv.org, launched in August 1991 by physicist Paul Ginsparg at Los Alamos National Laboratory, initially hosting preprints in high-energy physics and mathematics; by the mid-1990s, it had expanded to over 100,000 submissions annually, demonstrating the feasibility of unrestricted access without revenue from subscriptions.^[5] This was followed by the emergence of fully open-access peer-reviewed journals, such as Psycoloquy in 1989 and First Monday in 1996, though these remained niche amid dominant proprietary publishing.^[12] The formal open-access movement coalesced in the late 1990s and early 2000s, driven by rising journal subscription costs—averaging annual increases of 10-15% since the 1980s—and advocacy for public funding of research to yield public access. BioMed Central, founded in 1998 by Vitek Tracz as the first commercial open-access publisher, began issuing peer-reviewed journals in 2000 under an author-pays model, initially covering biomedical fields.^[13] Concurrently, the Public Library of Science (PLoS) formed in 2000 through an open letter signed by over 34,000 scientists demanding free access to publicly funded research; it launched its flagship journal, PLoS Biology, in 2003 as a high-impact, fully open-access title.^[14] These initiatives highlighted gold open access, where journals charge article processing fees (APCs) to offset costs while providing immediate, gratis access. The movement gained definitional clarity with the Budapest Open Access Initiative (BOAI) in February 2002, convened by the Open Society Institute, which coined the term "open access" and outlined two primary pathways: self-archiving in repositories (green OA) and direct publication in open-access journals (gold OA), emphasizing free readability, reusability, and irrevocability.^[15] This was reinforced by the Bethesda Statement on Open Access Publishing in June 2003, focusing on biomedical research and requiring immediate free access for funded work, and the Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities in October 2003, endorsed by institutions like the Max Planck Society, which broadened OA principles to include derivative works.^[13] Infrastructure followed with the Directory of Open Access Journals (DOAJ), established in 2003 at Lund University in Sweden to curate and index quality open-access titles, starting with 300 journals and growing to over 4,700 by 2009.^[16] By the mid-2000s, these developments spurred exponential growth in open-access journals, from approximately 300 in 2003 to nearly 5,000 by 2009, fueled by funder mandates (e.g., NIH policy in 2008) and institutional repositories, though early adoption was concentrated in sciences due to digital infrastructure advantages.^[17] Empirical analyses indicate that open-access articles garnered 18-50% more citations than toll-access counterparts in early years, incentivizing further journal launches despite debates over sustainability.^[9]

Open-Access Publishing Models

Gold and Diamond Models

The gold open access model refers to a publishing approach in which peer-reviewed research articles are made freely available immediately upon acceptance, without embargo periods, directly through the publisher's journal platform under an open license such as Creative Commons. This immediate accessibility applies to the version of record, ensuring the final published form is openly shared rather than relying on self-archived preprints or postprints. Funding for gold open access journals primarily derives from article processing charges (APCs), which authors, their institutions, or research funders pay to offset editorial, peer review, and dissemination costs, with APCs varying widely from under $1,000 to over $5,000 per article depending on the journal's prestige and operational scale.^[18][19][20] Key characteristics of the gold model include its alignment with mandates from funders like those in Plan S, which require immediate open access, and its provision of permanent, unrestricted online availability for reading, downloading, and reuse, subject to license terms. Unlike subscription-based models, gold open access shifts costs from readers to producers upfront, potentially broadening dissemination but introducing financial barriers for authors without grant support. As of 2023, gold open access accounted for a significant portion of new open access publications, with estimates indicating over 50% of open access articles published under this route in fields like biomedicine.^[3][21] The diamond open access model, alternatively termed platinum open access, extends gold open access principles by providing immediate, fee-free publication and access without charging APCs to authors or subscription fees to readers. This non-commercial structure relies on alternative revenue sources, such as institutional subsidies, university consortia, learned society endowments, or government grants, to cover operational expenses while maintaining academic control over editorial processes. Diamond journals emphasize community-driven governance, often hosted by non-profit entities, and are prevalent in disciplines like social sciences and humanities where APC burdens disproportionately affect unaffiliated scholars.^[22][23][24] Distinguishing features of diamond open access include its avoidance of author-pays economics, which mitigates risks of pay-to-publish incentives that can undermine selectivity in fee-based systems, and its focus on equitable access in regions with limited research funding. Globally, diamond open access represents approximately 17,000 journals as cataloged in directories like DOAJ, comprising about 73% of non-English-language open access journals, though it faces challenges in scalability due to dependence on sustained institutional support rather than market-driven APCs.^[25][26][20]

Green and Hybrid Models

The green open access model involves authors self-archiving versions of their manuscripts—such as preprints (submitted versions) or postprints (author-accepted manuscripts)—in institutional, disciplinary, or central repositories like PubMed Central or arXiv, often following a publisher-imposed embargo period ranging from 6 to 24 months.^[25][18] This pathway complies with many funders' mandates, such as those from the National Institutes of Health requiring deposit within 12 months of publication, and avoids article processing charges (APCs) by leveraging existing subscription-funded peer review while providing eventual public access.^[27] Publisher policies, tracked by services like SHERPA/RoMEO, vary in permissiveness, with some allowing immediate deposit of the final version and others restricting it to earlier drafts to protect subscription revenue.^[18] Empirical analyses show green OA enhances visibility and impact, with self-archived articles demonstrating an 18% citation advantage over non-open access counterparts, attributed to broader dissemination via repositories.^[28] However, embargoes can delay access, potentially limiting early citation accrual in fast-moving fields, and version control issues arise when readers encounter non-final manuscripts differing from the publisher's version of record.^[28] Adoption remains uneven, as it depends on author initiative and institutional support, with global repository deposits reaching millions annually but covering only a fraction of subscription-published output.^[25] The hybrid open access model applies to subscription journals where authors can pay an APC—typically $2,000 to $5,000—to release their article immediately under an open license, while non-paying articles stay paywalled.^[29][30] This "pay-to-open" option, offered by major publishers like Elsevier and Springer Nature since the early 2000s, aims to incrementally introduce openness without dismantling subscription systems, but it has drawn scrutiny for enabling "double dipping," where institutions pay both subscriptions and APCs for overlapping access rights.^[30] Transformative agreements, such as those negotiated by consortia like cOAlition S, bundle hybrid APCs into offset subscription deals, yet uptake data from over 5,000 hybrid journals indicate slow progress toward full openness, with hybrid articles comprising less than 10% of output in many titles as of 2021.^[31] Hybrid OA correlates with citation boosts similar to green routes, driven by immediate accessibility, though critics argue it sustains high publisher margins without systemic reform, as evidenced by stagnant overall open access rates in hybrid-heavy portfolios.^[28][32] Unlike pure green self-archiving, hybrid requires upfront funding, often straining non-grant-supported researchers, and its effectiveness hinges on transparent APC pricing and agreement terms to avoid inflating costs.^[30]

Evidence-Based Advantages

Citation and Dissemination Benefits

A systematic review of 134 empirical studies on open-access citation advantage (OACA) found that 47.8% confirmed higher citation rates for open-access articles compared to subscription-based ones, with 23.9% identifying advantages in subsets of samples, though self-selection bias—where higher-quality articles are preferentially made open access—complicates causal attribution.^[33] Recent analyses indicate the advantage persists after controlling for article quality and other confounders in many cases, with gold open-access models showing positive effects across disciplines.^[34] In ecology journals, open-access articles published between 2009 and 2013 garnered approximately one additional citation per year, accumulating to about five more citations after five years, a pattern consistent across global regions and economic statuses of citing authors.^[35] Similarly, in the Postgraduate Medical Journal, open-access articles from 2020–2021 exhibited significantly elevated citation counts relative to subscription articles, alongside heightened engagement metrics.^[36] Dissemination benefits manifest in increased visibility and usage, with open-access articles demonstrating substantially higher page views (β = 288.6) and PDF downloads (β = 119.0) than paywalled counterparts in medical publishing.^[36] This enhanced reach extends to broader citation diversity, as analyses of 19 million outputs from 2010–2019 reveal open-access works attract citations from a wider array of institutions, countries, and fields, measured via Shannon entropy and Gini-Simpson indices, with green open access showing particularly strong effects.^[37] Such patterns underscore open access's role in amplifying global knowledge transfer beyond traditional academic networks.^[38]

Accessibility and Economic Incentives

Open-access journals enhance research accessibility by eliminating subscription barriers, enabling unrestricted online access to articles without financial hurdles for readers. Empirical studies demonstrate that free access significantly boosts article downloads, with one review of randomized controlled trials and observational studies finding clear evidence of increased readership across disciplines, though citation impacts vary.^[39] This effect is pronounced in developing regions, where open-access outputs garner downloads from a broader geographic distribution, including higher engagement from low- and middle-income countries compared to paywalled counterparts.^[40] For instance, analyses of open-access books show usage in 61% more countries, with elevated downloads in nations like Indonesia, India, and China, facilitating knowledge dissemination to resource-constrained researchers and institutions.^[41] Economically, open-access models incentivize participation by shifting costs from reader-side subscriptions to author- or funder-paid article processing charges (APCs), potentially lowering long-term systemic expenses for libraries and universities. Proponents argue this reduces overall publishing and access costs for institutions and funding agencies, as libraries face declining needs for journal subscriptions once content is freely available, with estimates suggesting potential savings amid rising "big deal" bundle prices.^{[42] [43]} However, evidence on subscription cancellations remains limited; green open access has not yet produced widespread reductions, though gold open access could accelerate this if scaled.^[44] For authors, incentives include amplified visibility leading to career benefits, such as higher citation diversity from global sources, which correlates with professional advancement metrics in evaluation systems.^[38] Funders and institutions further promote open access through mandates, viewing it as an investment in public goods that maximizes taxpayer-funded research impact without perpetual access fees.^[45] These dynamics encourage a transition toward sustainable models like diamond open access, where no APCs are levied, preserving incentives for equitable participation.^[46]

Criticisms and Empirical Challenges

Predatory Publishing Phenomena

Predatory publishing encompasses the operation of journals and publishers that exploit the open-access model by charging authors substantial article processing charges (APCs) while delivering substandard or nonexistent peer review, editorial oversight, and indexing, thereby prioritizing revenue extraction over scientific rigor.^[47] These entities often mimic legitimate scholarly practices through aggressive solicitation, fabricated impact metrics, and promises of rapid publication, but produce outputs of dubious quality that fail to advance knowledge.^[48] The practice thrives under the gold open-access framework, where fees replace subscription income, creating perverse incentives for lax standards since rejection rates do not directly impact revenue.^[49] The phenomenon gained prominence in the early 2010s alongside the expansion of open-access publishing, with librarian Jeffrey Beall coining the term and launching a curated list in 2012 to highlight suspect operations.^[50] Beall's inventory grew to encompass over 1,000 publishers and thousands of journals by 2017, when external pressures led to its removal, though archived versions persist for reference.^[50] Subsequent tools, such as Cabell's Predatory Reports launched in 2017, have expanded detection efforts by assessing journals against 74 indicators of deceptive behavior, including editorial board misrepresentation and fee opacity, identifying 18,000 predatory titles as of 2024.^[51][52] Empirical data reveal the scale's escalation: articles in predatory outlets rose from roughly 53,000 in 2010 to 420,000 by 2014, with estimates exceeding 15,000 such journals active by 2021.^[53][54] Consequences include financial waste—often taxpayer-funded—career damage to authors via tainted credentials, and proliferation of flawed research that pollutes the literature, evidenced by higher retraction rates (14.6% of 2023–2025 retractions linked to predatory practices) and lower citation impacts compared to legitimate journals.^[55][56][6] This undermines public trust in science, particularly in fields with "publish or perish" pressures, where promotions in certain regions hinge on publication volume regardless of venue quality.^[56] Mitigation strategies encompass institutional policies barring predatory inclusions in evaluations, enhanced author education, and criteria-based directories like the Directory of Open Access Journals (DOAJ), which vet for transparency and sustainability.^[49] However, evolving tactics—such as hijacked journals and pseudo-conferences—persist, necessitating ongoing vigilance, as predatory entities adapt to blacklist scrutiny by rebranding or targeting less-resourced researchers.^[57]

Quality Assurance and Financial Burdens

Open-access publishing faces significant challenges in maintaining rigorous quality assurance, primarily due to the proliferation of predatory journals that prioritize revenue from article processing charges (APCs) over substantive peer review. Predatory outlets, which emerged prominently after the shift to author-pays models, often simulate editorial processes but accept manuscripts with minimal scrutiny, leading to the dissemination of flawed or fabricated research.^[58] Empirical analyses indicate that articles from such journals are cited in systematic reviews and policy documents, potentially skewing evidence-based decisions in fields like public health.^[59] For instance, a 2022 study found predatory publications infiltrating guidance documents, highlighting systemic failures in distinguishing legitimate from illegitimate sources.^[60] Efforts to assure quality, such as inclusion in directories like the Directory of Open Access Journals (DOAJ), provide some vetting, but empirical evidence reveals uneven enforcement and persistent vulnerabilities. Recent threats include "paper mills" generating fabricated papers for sale, exacerbating quality erosion in open-access respiratory medicine journals as of 2025.^[61] Unlike subscription-based models, where gatekeeping aligns incentives with reputational risk, open-access's fee-driven structure can incentivize volume over rigor, with studies showing higher retraction rates in low-fee predatory venues compared to established publishers.^[62] This has prompted calls for enhanced transparency in peer-review processes, though implementation remains inconsistent across platforms.^[63] Financial burdens in open-access publishing stem from escalating APCs, which shift costs from libraries to authors and funders, often without proportional quality gains. As of 2024, the global average APC stands at approximately $1,626, with ranges from $500 to over $6,000 per article depending on the journal and publisher.^[64] Total global expenditures on APCs reached an estimated $8.3 billion from 2019 to 2023, reflecting a model where top publishers capture the majority of fees—76% in one UK analysis—while costs rose by 6.5% in list prices for fully open-access journals by early 2025.^{[65] [66]} These charges impose inequities, particularly on researchers in underfunded institutions or developing countries, where waivers are available but insufficient to offset barriers to publication.^[67] Hybrid journals exacerbate burdens through "double-dipping," requiring ongoing subscription payments alongside APCs for open-access options, leading APCs to consume up to 10% of some institutional budgets.^[68] Funders like the NIH have considered caps, such as $2,000 per paper, to mitigate escalation near the $2,177 average, but such measures risk concentrating publications among well-resourced entities, undermining open access's accessibility goals.^[69]

Open-Access Journals in Biological and Agricultural Sciences

Agriculture

Open-access journals in agriculture provide unrestricted access to peer-reviewed research on topics including crop cultivation, livestock management, soil fertility, pest control, and agribusiness economics, supporting advancements in food production and sustainability amid global challenges like population growth and climate variability. The Directory of Open Access Journals (DOAJ) indexes 1,077 such journals as of the latest available data, reflecting a diverse ecosystem often featuring contributions from institutions in developing regions where agricultural research directly addresses local food security needs.^[70] These publications typically operate under gold open-access models, charging article processing fees to authors while ensuring free reader access, though diamond models without fees exist in some university-led outlets.^[4] Prominent examples include Agriculture, an MDPI publication established in 2011 that semimonthly disseminates findings on crop and animal production, soil and water resources, and environmental impacts of farming technologies, with a 2024 Journal Impact Factor of 3.6 based on Clarivate metrics.^[71][72] Journal of Agriculture and Food Research, launched by Elsevier, emphasizes interdisciplinary studies in agricultural production processes and food quality assessment, maintaining rigorous peer review as a diamond open-access title without author fees in its core model.^[73] Discover Agriculture, a Springer Nature journal, covers empirical research in agricultural technologies, policy implications, and ecosystem services, indexed in DOAJ and prioritizing high-impact, data-driven articles since its inception.^[74] Other notable DOAJ-listed journals include Selcuk Journal of Agriculture and Food Sciences, published by Selcuk University since 2013, which addresses plant protection, field crops, and food technology with a focus on regional Mediterranean agriculture.^[75] The Journal of Agricultural Sciences, from Sri Lanka, explores agribusiness, livestock genetics, and economic modeling, promoting South Asian perspectives on sustainable intensification.^[76] These outlets collectively enhance empirical knowledge transfer, though their variable citation impacts—often lower than subscription-based counterparts—highlight ongoing debates on quality consistency in open-access agriculture publishing, where DOAJ's inclusion criteria mandate transparent peer review but do not guarantee equivalence to traditional metrics.^[4]

Biology

Open-access journals in biology provide unrestricted access to peer-reviewed research across subdisciplines including molecular biology, genetics, physiology, and evolutionary biology, promoting wider dissemination and citation of findings. As of March 2024, the Directory of Open Access Journals indexes 1,015 biology-specific titles, reflecting substantial growth driven by funder mandates and institutional policies favoring accessibility over subscription barriers.^[77] These publications often operate under article processing charge (APC) models, with fees varying by publisher, though waivers are available for eligible authors to mitigate financial barriers.^[78] Prominent examples demonstrate diverse scopes and operational models, from nonprofit initiatives emphasizing high-impact original research to broader platforms accepting rigorous studies of varying significance. These journals collectively enhance empirical progress in biology by enabling global access, though empirical studies indicate variable quality controls amid APC incentives, with established titles maintaining higher citation rates through stringent selection.^[77][90]

Botany

Open-access journals in botany disseminate research on plant taxonomy, physiology, ecology, genetics, and applied sciences without subscription barriers, often funded via article processing charges. The Directory of Open Access Journals (DOAJ) indexes vetted titles that adhere to open access principles and peer-review standards.^[4] Prominent examples include:

• AoB Plants, published by Oxford University Press, which focuses on environmental plant biology, functional ecology, and integrative plant science, emphasizing rapid publication of high-quality research.^[91]
• Botanical Studies, a SpringerOpen journal covering molecular biology, ecology, biochemistry, microbiology, taxonomy, and plant physiology, with articles peer-reviewed for originality and rigor.^[92]
• Botanical Sciences, issued by the Botanical Society of Mexico, addressing plant sciences including ecology, taxonomy, systematics, phylogeny, and reproductive biology, with a emphasis on Mexican and Latin American flora.^[93]
• Journal of Applied Botany and Food Quality, which publishes on plant nutrition, cultivation, breeding, stress responses, and phytomedicine, prioritizing practical applications in agriculture and quality assessment.^[94]
• Applications in Plant Sciences, the gold open access journal of the Botanical Society of America via Wiley, dedicated to new methods, protocols, and tools for plant research, including genomic and imaging techniques.^[95]
• Frontiers in Plant Science, a multidisciplinary platform from Frontiers Media with sections on physiology, genetics, pathology, and systems biology; it reported a 2023 impact factor of 4.8 based on Scopus data.^[96]
• Plant Direct, a collaborative Wiley journal supported by the American Society of Plant Biologists and Society for Experimental Biology, offering sound science across plant genetics, physiology, and ecology without bias toward high-impact topics.^[97]

These journals contribute to broader accessibility in botany, though quality varies; DOAJ inclusion requires transparent policies, but independent evaluation of peer-review processes is recommended.^[4]

Ecology

Ecosphere is the fully open-access journal of the Ecological Society of America, publishing research across ecological subdisciplines including community ecology, ecosystem processes, and conservation biology. Launched in 2010, it emphasizes rapid peer review and broad dissemination without subscription barriers. Its 2023 impact factor stands at 2.9, reflecting its role in advancing empirical ecological studies.^[98][99] Ecology and Evolution, published by Wiley in partnership with the British Ecological Society, covers interdisciplinary topics in ecology, evolutionary biology, and conservation since its inception as a broad open-access platform. The journal prioritizes rigorous peer-reviewed articles on mechanisms driving biodiversity and species interactions. It holds a 2023 impact factor of 2.3 and is indexed in DOAJ, ensuring transparency in its diamond-like access model for authors.^[100][101] Ecology & Society, established in 1997, focuses on social-ecological systems, resilience, and adaptive management through interdisciplinary peer-reviewed research. As one of the earliest fully open-access journals in the field, it integrates empirical data on human-environment interactions without article processing charges in its traditional model. Its 2021 impact factor was 5.275, highlighting its influence on policy-relevant ecological analyses.^[102][103] Global Ecology and Conservation, an Elsevier open-access journal founded in 2014, addresses global patterns in biodiversity, habitat dynamics, and conservation strategies via data-driven studies. It undergoes standard peer review and publishes on threats to species richness and ecosystem services. The journal's 2023 impact factor is 3.4, supporting its credibility among major publishers.^[104][105] These journals exemplify reputable open-access venues in ecology, often backed by professional societies or established publishers to mitigate risks associated with lower-quality outlets, as identified in predatory publishing watchlists.^[50] Selection prioritizes DOAJ-indexed titles with verifiable peer review processes and avoidance of entities flagged for lax standards.^[4]

Nutrition

Open-access journals in nutrition encompass peer-reviewed publications that provide unrestricted access to research on human dietary patterns, nutrient metabolism, clinical interventions, and public health nutrition. These journals, often indexed in the Directory of Open Access Journals (DOAJ), support empirical studies ranging from epidemiological surveys to randomized controlled trials, enabling broader dissemination amid rising concerns over paywalled content limiting access in evidence-based fields like nutritional science.^[4] Prominent titles demonstrate varying scopes, with some emphasizing molecular mechanisms and others focusing on population-level outcomes, as evidenced by citation metrics from Google Scholar where top performers exceed h5-index values of 100.^[106] Key examples include:

• Nutrients (established 2009, MDPI): An international semimonthly journal publishing original research on human nutrition topics, including micronutrient deficiencies and dietary interventions; it ranks highly in citation impact with an h5-index of 213.^[107][106]
• Frontiers in Nutrition (established 2014, Frontiers Media): A multidisciplinary outlet integrating dietary behavior, agronomy, and food science with health outcomes, featuring sections on clinical nutrition and epidemiology; h5-index of 104.^{[108][109][106]}
• Nutrition Journal (established 2002, BioMed Central): Focuses on surveillance, epidemiologic, and intervention studies in human nutrition, including eating patterns and chronic disease prevention.^[110][111]
• Current Developments in Nutrition (established 2017, American Society for Nutrition): Publishes original articles, brief communications, and research methods in diet and medical nutrition therapy.^[112][113]
• Clinical Nutrition Open Science (established 2021, Elsevier, official journal of ESPEN): Covers microbiota, nutrigenomics, metabolism, and nutrient physiology in clinical contexts.^[114][115]
• Nutrition & Metabolism (established 2004, BioMed Central): Addresses obesity, exercise physiology, metabolic syndrome, and diabetes through nutritional lenses.^[116]
• Journal of Nutritional Science (established 2012, Cambridge University Press for The Nutrition Society): An online-only journal accepting high-quality research across nutritional disciplines, from basic science to applied interventions.^[117]

These journals collectively advance causal understanding of nutrition's role in health, with article processing charges funding operations while DOAJ vetting mitigates predatory risks through criteria like transparent peer review and editorial standards.^[4] Empirical data from indexing services confirm their adherence to open-access principles, though researchers should evaluate individual articles for methodological rigor beyond journal prestige.^[4]

Open-Access Journals in Physical and Earth Sciences

Astronomy

The Astrophysical Journal, published by the Institute of Physics (IOP) Publishing on behalf of the American Astronomical Society, became a fully open-access journal in January 2024, focusing on theoretical and observational research in astronomy and astrophysics, including stars, galaxies, and cosmology.^[118] It maintains rigorous peer review and is indexed in Scopus and Web of Science, with an impact factor of 7.2 in 2023.^[119] The Astronomical Journal, also affiliated with the American Astronomical Society and published by IOP, transitioned to full open access in 2022, emphasizing original research on solar system bodies, exoplanets, and stellar dynamics.^[120] Peer-reviewed submissions undergo an average of 19 weeks from submission to publication, and it is indexed in DOAJ, Scopus, and Web of Science.^[120] The Open Journal of Astrophysics, an arXiv overlay journal launched in 2020, operates as a diamond open-access publication with no article processing charges (APCs), reviewing preprints in astrophysics, cosmology, and astroparticle physics.^[121] It relies on volunteer editors from established institutions for peer review and is listed in DOAJ, prioritizing accessibility without financial barriers to authors.^[121] Open Astronomy, published by De Gruyter, covers all aspects of astronomy and astrophysics from solar system studies to cosmology, as a peer-reviewed open-access journal since 2012.^[122] It is indexed in Scopus and features both original articles and reviews, with APCs funding its operations.^[122] Frontiers in Astronomy and Space Sciences, part of the Frontiers portfolio, publishes multidisciplinary open-access research across astronomy subfields, including planetary science and high-energy astrophysics, with peer review managed through an interactive platform.^[123] Indexed in Scopus and Web of Science, it reported an impact factor of 2.5 in 2023, though its review process has drawn scrutiny for efficiency claims versus traditional rigor.^[124] Discover Space, launched by Springer Nature in 2023, focuses on space science research from observational astronomy to mission data analysis, as a fully open-access journal indexed in Web of Science's Science Citation Index Expanded.^[125] It emphasizes interdisciplinary contributions and charges APCs, with early volumes demonstrating coverage of satellite observations and cosmic phenomena.^[125]

Chemistry

Open-access journals in chemistry provide unrestricted access to peer-reviewed research across subfields such as organic, inorganic, physical, analytical, and computational chemistry, often supported by article processing charges (APCs) or diamond models without fees to authors. Established publishers like the American Chemical Society (ACS), Royal Society of Chemistry (RSC), and Beilstein-Institut maintain high editorial standards, rigorous peer review, and low retraction rates, distinguishing them from lower-quality or predatory outlets that may prioritize volume over scrutiny.^[126][127] As of October 2024, the Directory of Open Access Journals (DOAJ) indexes 636 chemistry journals meeting quality criteria, including transparency in peer review and licensing.^[128] Reputable fully open-access examples include:

• Chemical Science: Published by the RSC since 2010, this flagship journal disseminates significant advances in fundamental chemical sciences, with a focus on innovative, high-impact work across all chemistry disciplines; it operates on an APC model but offers waivers for certain cases.
• ACS Central Science: A diamond open-access journal from ACS launched in 2015, covering multidisciplinary chemical research without APCs, emphasizing transformative discoveries and broad accessibility funded by society sponsorship.^[129]
• ACS Omega: ACS's multidisciplinary open-access outlet since 2016, publishing peer-reviewed articles in chemistry and related fields with an APC structure; it prioritizes reproducibility and serves as a venue for solid, applied research not always suited to higher-impact hybrid journals.^[129]
• Beilstein Journal of Organic Chemistry: A diamond open-access publication of the Beilstein-Institut since 2005, dedicated to organic chemistry including synthesis, mechanisms, and applications; it relies on institutional funding without APCs or subscriptions, ensuring free access and author rights retention.
• ChemistryOpen: Issued by Chemistry Europe (a consortium including Wiley) since 2012, this fully open-access journal spans general chemistry topics with interdisciplinary appeal, using APCs to cover costs and featuring rapid publication timelines.^[130]
• RSC Advances: An RSC open-access journal established in 2011, encompassing broad chemical research from materials to biochemistry; it employs APCs and publishes a high volume of peer-reviewed papers, with editorial oversight to maintain quality amid scale.
• Journal of Cheminformatics: Published by Springer Nature (BMC) since 2009, focusing on computational methods, data handling, and informatics in chemistry; diamond open-access via sponsor funding, it supports open data and software deposition for reproducibility.

These journals, affiliated with longstanding chemical societies, demonstrate lower risks of bias or fabrication compared to independent or high-volume publishers, as evidenced by their integration into major indexes like Scopus and Web of Science.^[4] Researchers should verify current indexing and metrics, as open-access models evolve with funding shifts.^[128]

Earth Sciences

Open-access journals in Earth Sciences facilitate unrestricted dissemination of research in disciplines including geology, geophysics, paleoclimatology, seismology, and planetary sciences, often supported by article processing charges or society funding. As of March 2024, the Directory of Open Access Journals indexes 237 titles under relevant categories such as geology, geodesy, and geophysics.^[131] These publications prioritize peer-reviewed content, with many affiliated to professional organizations like the European Geosciences Union (EGU), which maintains 19 open-access journals via Copernicus Publications, and the American Geophysical Union (AGU), offering 12 such titles in partnership with Wiley.^[131] Prominent examples include Frontiers in Earth Science, launched in 2014 by Frontiers Media, which addresses interdisciplinary topics across the atmosphere, lithosphere, hydrosphere, and structural geology.^[132] Hydrology and Earth System Sciences (HESS), an EGU journal published by Copernicus since 1997, specializes in hydrometeorology, ecohydrology, water resources, and biogeochemical cycles, maintaining diamond open access without author fees for certain contributions.^[133] Earth and Space Science, established by AGU in 2014, publishes original research spanning Earth, planetary, and heliophysics domains under a fully open-access model funded by article processing charges.^[134] Earth, a quarterly MDPI journal initiated in 2020, covers broad earth science themes including geomorphology, remote sensing, and natural hazards through rapid peer review.^[135] Open Geosciences, from De Gruyter since 2009, encompasses all Earth Sciences subfields with emphasis on geochemistry, sedimentology, and tectonics, adhering to Creative Commons licensing.^[136] Earth Science, Systems and Society, launched by the Geological Society of London in 2021, integrates geosciences with societal impacts, focusing on seismology, volcanology, and geohealth in an open-access format.^[137] These journals collectively enhance accessibility but vary in scope and rigor, with society-backed ones like HESS demonstrating sustained impact through citation metrics exceeding those of newer entrants.^[133] Researchers should verify indexing in databases like Scopus or Web of Science for credibility, as open access does not guarantee quality absent rigorous editorial standards.^[131]

Energy

Energies is a peer-reviewed, fully open-access journal published semimonthly by MDPI, covering scientific research, technology development, engineering policy, and management studies related to energy supply, conversion, dispatch, final use, and underlying physical and chemical processes.^[138] It reports an impact factor of 3.2 for 2024.^[138] IEEE Open Access Journal of Power and Energy is a fully open-access journal published by IEEE, emphasizing the development, planning, design, construction, maintenance, installation, and operation of equipment and power systems for electric energy conversion, generation, transmission, distribution, storage, usage, measurement, and control.^[139] It succeeded the IEEE Power and Energy Technology Systems Journal and accepts both academic and practice-oriented submissions.^[139] Advances in Applied Energy is a peer-reviewed, fully open-access journal launched in 2021 and published by Elsevier, focusing on energy innovation, transition, renewable energy, sustainability, and integrated energy systems.^[140] Frontiers in Energy Research is a fully open-access journal published by Frontiers Media, addressing advances in sustainable power generation, clean technologies, and energy policy aimed at a low-carbon future, including bioenergy, solar energy, and process engineering.^[141][142] International Journal of Energy Research is a peer-reviewed, fully open-access journal published by Wiley, encompassing energy production, management, conversion, storage, and renewable sources for researchers, engineers, and policymakers.^[143][144]

Materials Science

Open-access journals in materials science facilitate unrestricted dissemination of peer-reviewed research on the synthesis, structure, properties, and applications of materials, including metals, polymers, ceramics, composites, and nanomaterials. These publications often operate under creative commons licenses and may charge article processing fees to authors, enabling free reader access while covering editorial and production costs. Notable examples include journals indexed in directories like the Directory of Open Access Journals (DOAJ), which verify compliance with open-access standards such as peer review and transparent policies.^[4]

• Materials (MDPI): An international peer-reviewed journal publishing original research and reviews on materials science and engineering, including advanced materials for energy and biomedical applications; semimonthly publication with a focus on experimental and theoretical studies.^[145]
• Advances in Materials Science and Engineering (Hindawi): Covers topics in materials processing, mechanical behavior, and novel materials like nanomaterials and biomaterials; emphasizes engineering applications and interdisciplinary approaches.^[146]
• AIMS Materials Science (AIMS Press): Publishes high-quality papers on biological materials, composites, ceramics, polymers, and magnetic materials, with an emphasis on innovative synthesis and characterization techniques.^[147]
• Science and Technology of Advanced Materials (Taylor & Francis): Focuses on biomedical and bio-inspired materials, energy storage materials, environmental applications, and nanoscale structures; known for rapid publication and high-impact reviews.^[148]
• Nano Materials Science (KeAi Publishing): Specializes in nanometer-scale materials, devices, microstructures, properties, and preparation methods, bridging nanotechnology with practical engineering solutions.^[149]
• Materials Advances (Royal Society of Chemistry): A broad-scope journal addressing synthesis, characterization, and performance of materials across chemistry and physics interfaces, including sustainable and functional materials.^[150]
• Oxford Open Materials Science (Oxford University Press): Publishes novel research and reviews spanning computational modeling, experimental fabrication, and real-world deployment of materials for emerging technologies.^[151]
• Journal of Materials Science: Materials in Medicine (Springer): Examines biomaterials, tissue engineering, and medical devices, integrating materials science with biomedical engineering principles.^[152]

Physics

New Journal of Physics, published by the Institute of Physics Publishing since 1998, is a fully open-access journal covering original research across all areas of physics with broad interdisciplinary appeal, including quantum information, condensed matter, and biophysics; it maintains high standards through rigorous peer review and has an impact factor of 3.8 as of 2023.^[153][154] Physical Review X, launched by the American Physical Society in 2011, serves as a flagship open-access journal for multidisciplinary physics research, emphasizing groundbreaking advances in areas like quantum science, soft matter, and complex systems; it features selective publication with an impact factor exceeding 12 in recent years, supported by article processing charges.^[155] Physics Open, an Elsevier journal established in 2019, provides open access to peer-reviewed articles spanning experimental and theoretical physics, including nuclear, particle, and applied fields; it aims for rapid dissemination without subscription barriers, funded via APCs, and is indexed in Scopus.^[156][157] Open Physics, formerly known as Open Physics Journal and published by De Gruyter since 2014, focuses on fundamental research in all physics subfields such as atomic, condensed matter, and optics; it operates under a diamond open-access model in some cases but primarily uses APCs, with peer review ensuring quality despite varying impact metrics.^[158][159] Additional specialized open-access outlets include AIP Advances from the American Institute of Physics, which covers applied physics innovations since 2011 with no publication fees for authors, and contributions from the SCOAP³ initiative enabling open access for high-energy physics journals like Journal of High Energy Physics since 2014, converting subscription-based content to free availability through consortium funding rather than individual APCs.^[160][157] These journals, primarily from established professional societies, prioritize empirical rigor and peer validation over predatory models, though researchers should verify indexing in databases like DOAJ for credibility.^[4]

Open-Access Journals in Formal Sciences

Computer Science

Open-access journals in computer science disseminate peer-reviewed research without paywalls, spanning subdisciplines such as algorithms, artificial intelligence, software engineering, and data structures. These publications often operate under diamond or gold models, with some imposing article processing charges (APCs) while others forgo fees to promote accessibility. As of March 2024, the Directory of Open Access Journals (DOAJ) indexes 554 computer science journals, reflecting growth in the field driven by digital archiving and institutional mandates for open dissemination.^[161] Prominent examples include established venues with rigorous peer review and indexing in databases like Scopus, ensuring visibility and credibility. Selection prioritizes journals with verifiable open-access status, excluding predatory outlets lacking transparent editorial processes.

• IEEE Access: A multidisciplinary open-access journal published by the Institute of Electrical and Electronics Engineers (IEEE) since 2013, covering computer science topics including signal processing and emerging computing paradigms; it applies APCs but maintains high citation rates and Scopus indexing.^[161]
• Journal of Artificial Intelligence Research (JAIR): A diamond open-access journal founded in 1993 by the AI Access Foundation, specializing in foundational and applied AI research with no APCs; it emphasizes archival-quality papers and is indexed in major databases without reliance on subscription revenue.^[162]
• IEEE Open Journal of the Computer Society (OJ-CS): Launched by IEEE as a fully open-access venue for high-impact computer science research, focusing on rapid publication of novel contributions across computing subfields; it underwent peer review for Scopus inclusion to affirm quality.^[163]
• Journal of Universal Computer Science (J.UCS): An open-access periodical established in 1995 by institutions including Graz University of Technology, addressing theoretical and applied computer science topics like knowledge engineering and pattern recognition; it remains free to publish and read, with ongoing Scopus coverage.^[164]
• SN Computer Science: A Springer Nature open-access journal accepted into Scopus indexing starting from its inaugural volume, publishing peer-reviewed articles in core computer science areas such as data mining and mobile computing; it supports APC-funded accessibility for broad dissemination.^[165]
• International Journal of Advanced Computer Science and Applications (IJACSA): Published by The Science and Information Organization since 2010, this open-access journal covers advanced applications in computer science and is Scopus-indexed, with free reader access though APCs apply for authors.^[166]
• Open Computer Science: A De Gruyter open-access journal initiated in 2018, focusing on algorithms, artificial intelligence, and networking; it is listed in DOAJ for its peer-reviewed content in theoretical computer science.^[167]

These journals exemplify the shift toward open models in computer science, where empirical validation through citations and indexing outweighs traditional prestige metrics, though APC dependencies raise equity concerns for unaffiliated researchers.^[161]

Mathematics

Open-access journals in mathematics encompass a range of peer-reviewed publications that provide unrestricted access to research without subscription fees, often operating on diamond models funded by universities, societies, or grants to eliminate article processing charges. These journals emerged prominently in the 1990s with the advent of electronic publishing, enabling rapid dissemination of results in pure and applied areas such as algebra, analysis, geometry, and topology. Unlike some fields, mathematics has seen strong adoption of no-fee open access due to community-driven initiatives prioritizing accessibility over commercial models, though quality varies and rigorous peer review remains essential for credibility.^[168] The New York Journal of Mathematics, founded in 1993 by the University at Albany, was the first fully electronic general mathematics journal, offering refereed publications across broad mathematical topics with no charges to authors or readers.^[169] Documenta Mathematica, established in 1996 by the Deutsche Mathematiker-Vereinigung, publishes high-quality articles in all mathematical fields, maintained as a diamond open-access venue with free access and no author fees, emphasizing international scope and careful refereeing.^{[170] [171]} Acta Mathematica, originating in 1882 under the Royal Swedish Academy of Sciences and now managed by Institut Mittag-Leffler, transitioned to full open access for recent issues, delivering seminal works in diverse mathematical domains without processing fees.^[172] Communications of the American Mathematical Society, launched in 2021 by the AMS, operates as a diamond open-access journal for innovative, high-impact research across mathematics, supported by society sponsorship.^[173] Comptes Rendus - Mathématique, published by the French Academy of Sciences, functions as a diamond open-access outlet for original research articles and surveys, with rapid peer review and no costs to contributors. Specialized diamond journals further support subfields, such as the Electronic Journal of Combinatorics (1994, combinatorial mathematics) and the Journal of Integer Sequences (1998, sequences and number theory), both institutionally backed with no fees. These examples illustrate mathematics' emphasis on sustainable, community-funded open access, contrasting with APC-dependent models criticized for potential barriers to entry.^[174]

Statistics

Open-access journals in statistics encompass peer-reviewed publications that freely disseminate research on theoretical foundations, computational methods, applied techniques, and interdisciplinary applications such as data science education. These journals, often supported by professional societies like the Institute of Mathematical Statistics (IMS) and the American Statistical Association (ASA), prioritize accessibility while maintaining rigorous refereeing standards equivalent to traditional outlets.^[175][176] Prominent examples include:

• Electronic Journal of Statistics: Published by the IMS since 2007, this journal features research articles and short notes on theoretical, computational, and applied statistics, with all content openly accessible upon publication following peer review.^[175][177]
• Journal of Statistical Software: Launched in 1996, it specializes in the development and evaluation of statistical software, computational algorithms, and their applications, offering all articles under open licenses for unrestricted use.^[178][179]
• Journal of Statistics and Data Science Education: An ASA publication focused on pedagogy in statistics, probability, and data science, providing open-access articles to support educational advancements since its inception.^[176][180]
• ASA Discoveries: Introduced by the ASA, this open-access venue highlights innovative, high-impact statistical research across disciplines, emphasizing novel methodologies and discoveries.^[176]
• REVSTAT - Statistical Journal: Issued by the Portuguese Statistical Society and partners, it covers statistical inference, stochastic processes, and applied data analysis, with full open access to peer-reviewed content.^[181]
• Research in Statistics: A Taylor & Francis journal dedicated to advancements in statistical theory, probability, and data applications, ensuring immediate open access for global readership.^[182]

These outlets contribute to broader dissemination but vary in scope and citation impact, with society-backed journals like those from IMS and ASA generally upholding high scholarly standards through established editorial processes.^[176][175]

Open-Access Journals in Health and Applied Sciences

Bioethics

BMC Medical Ethics is a peer-reviewed open-access journal published by BioMed Central, focusing on ethical issues in biomedical research, clinical practice, and healthcare.^[183] It features original research articles, reviews, and commentaries, with a 2024 Journal Impact Factor of 3.1 and a 5-year Impact Factor of 3.7.^[184] Voices in Bioethics, affiliated with Columbia University Libraries, is a peer-reviewed open-access journal addressing bioethical challenges at the intersections of medicine, law, philosophy, and public health.^[185] It began open-access publication in 2013 and accepts submissions on domestic and global ethical topics.^[186] The Canadian Journal of Bioethics is a bilingual (English and French) peer-reviewed open-access journal that publishes theoretical, applied, and empirical bioethics research from an international perspective.^[187] Launched in 2018, it emphasizes diverse scholarly forms including articles and case studies.^[188] Global Bioethics is a peer-reviewed open-access journal dedicated to health policy, ethics, and bioethics in global contexts, particularly in developing regions.^[189] Indexed in DOAJ since 2018, it promotes interdisciplinary discussions on ethical challenges in international health.^[189] The Journal of Law and the Biosciences, published by Oxford University Press, is a diamond open-access peer-reviewed journal exploring legal, ethical, and policy issues in biosciences.^[190] It features rigorous analysis of topics like genetic technologies and regulatory frameworks, with no author fees.

Medicine, Pharmaceuticals, and Health Sciences

BMJ Open, launched in 2011 by BMJ Publishing Group, is a multidisciplinary open-access journal that publishes original research across all medical disciplines and therapeutic areas, emphasizing transparency and reproducibility in clinical studies.^[191] JAMA Network Open, established in 2018 by the American Medical Association, provides open access to peer-reviewed research on topics including hypertension, diabetes, and public health interventions, with over 1,000 articles published annually as of 2023.^[192] eClinicalMedicine, part of The Lancet family and published by Elsevier since 2019, focuses on clinical research with global impact, including trials and observational studies, and is indexed in PubMed without author fees in select regions via geographical pricing.^[193] In pharmaceuticals, Pharmaceuticals, an MDPI journal started in 2009, covers medicinal chemistry, drug design, and pharmacology, publishing monthly with peer-reviewed articles on novel compounds and therapeutic agents.^{[194] [195]} The Journal of Pharmacy & Pharmaceutical Sciences, founded in 1998 as the first open-access journal in its field, disseminates research on pharmacokinetics, drug delivery, and pharmaceutical biotechnology, hosted by Frontiers Partnerships with no publication fees for authors.^[196] Acta Pharmaceutica Sinica B, a diamond open-access journal with no fees, achieved a 2022 impact factor of 14.903 and publishes high-quality work on pharmaceutical sciences, indexed in Scopus and SCIE.^[197] For broader health sciences, Healthcare, another MDPI title launched in 2013, addresses health systems, policy, and technology, including regulatory aspects of care delivery.^[198] The Open Public Health Journal, published since 2009 by Bentham Open, features research on epidemiology, preventive medicine, and health promotion, with peer-reviewed articles available without subscription.^[199] Diamond open-access options like The Permanente Journal, indexed in MEDLINE since 1957 and fully open since adopting the model, prioritize clinical medicine and health delivery science funded by institutional support rather than author fees.^[200] These journals facilitate empirical advancement in the field, though readers should assess individual articles for methodological rigor given varying peer-review stringencies across publishers.^[201]

Engineering

Open-access journals in engineering disseminate peer-reviewed research across subdisciplines including civil, mechanical, electrical, and biomedical engineering, typically under Creative Commons licenses to enable unrestricted reading, downloading, and reuse. These publications address the need for barrier-free access to technical advancements, though most operate via author article processing charges (APCs) averaging $1,000–$3,000 to cover editorial and production costs. As of March 2024, the Directory of Open Access Journals (DOAJ) indexes 1,724 engineering-specific entries, reflecting growth driven by funder mandates and institutional repositories.^[202] Reputable outlets are affiliated with established societies or publishers like IEEE and Elsevier, ensuring rigorous peer review, whereas unaffiliated or low-barrier journals warrant scrutiny for potential quality variances.^[4] IEEE Access, launched in 2013 by the Institute of Electrical and Electronics Engineers (IEEE), is a multidisciplinary open-access journal spanning electrical, electronics, computing, and applied engineering fields, with an emphasis on novel applications and rapid dissemination via continuous online publication. It maintains a 4–6 week peer-review timeline and has published over 100,000 articles by 2025, achieving a 2023 impact factor of 3.476 per Journal Citation Reports.^{[203][204][205]} Advances in Mechanical Engineering, a Sage Journals publication since 2009, focuses on mechanical systems, thermodynamics, manufacturing processes, and vibration analysis, accepting original research and reviews with JCR indexing for bibliometric evaluation. It prioritizes practical engineering solutions and reports an acceptance rate under 30% based on rigorous double-blind review.^[206][207] CivilEng, established in 2020 by MDPI, is a quarterly open-access outlet for civil engineering topics including structural dynamics, geotechnical engineering, and sustainable infrastructure, with articles undergoing single-blind peer review and DOAJ certification for transparency. It emphasizes interdisciplinary approaches to urban development challenges.^[208][209] Engineering, sponsored by the Chinese Academy of Engineering and published monthly via Elsevier since 2015, covers broad engineering innovations in areas like energy systems, materials, and environmental technologies, featuring high-profile reviews and original articles vetted by international editorial boards. Its 2023 impact factor stands at 12.8, reflecting influence in translational research.^[210][210] The Journal of Engineering, issued by the Institution of Engineering and Technology (IET) since 2014, targets biomedical, civil, electrical, and mechanical engineering intersections, offering fully open access with a focus on conference-derived and standalone papers under a diamond model minimizing APCs for select contributors. It indexes in Scopus and maintains quality through thematic issues.^[211] These journals exemplify credible open-access models, backed by professional societies or vetted publishers, contrasting with less scrutinized outlets; researchers should verify indexing in Scopus or Web of Science for sustained reputability.^[212][213]

Robotics

Frontiers in Robotics and AI is a peer-reviewed open-access journal published by Frontiers Media, focusing on robotics, computational intelligence, biomedical robotics, field robotics, and human-robot interaction; it was established in 2014.^[214]
International Journal of Advanced Robotic Systems is a peer-reviewed open-access journal from SAGE Publishing, covering mobile robots, bioinspired robotics, artificial intelligence applications in robotics, human-robot interaction, and service robotics; it has been active since 2004 with an impact factor of 2.1 as of 2023.^[215]
Journal of Robotics is a peer-reviewed open-access journal published by Hindawi (Wiley), dedicated to advancements in robotics and automation, including robot design, control systems, and applications; it was launched in 2008.^[216][217]
Robotics is a peer-reviewed open-access journal by MDPI, addressing robotics science, engineering, and technology across mechanical, electrical, and software aspects; it publishes monthly and began in 2012.^[218]
npj Robotics is a peer-reviewed open-access journal from Nature Portfolio, emphasizing embodied intelligence, bio-inspired AI, neuromorphic sensing, soft robotics, and living machines; it was launched in 2024.^[219]
Robotics: Integration, Manufacturing and Control (RIMC) is a peer-reviewed open-access journal covering robotic systems, human-robot collaboration, robotics in manufacturing, Industry 4.0 applications, and control algorithms; it received DOAJ indexing in 2025.^[220]

Open-Access Journals in Social Sciences and Humanities

Economics and Finance

Theoretical Economics is a diamond open-access journal published by the Econometric Society since 2006, specializing in rigorous theoretical contributions to economic theory, game theory, and related mathematical modeling, with no article processing charges and full peer review equivalent to top-tier subscription journals like Econometrica. Its selective acceptance process ensures high scholarly standards, publishing approximately 20-30 articles annually as of 2023 data.^[221] Quantitative Economics, also from the Econometric Society and launched in 2010, operates as diamond open-access, emphasizing empirical, computational, and quantitative methods in economics, including structural estimation and policy analysis, with rigorous double-blind peer review and no fees to authors. The journal maintains quality through association with a prestigious society, achieving citation impacts competitive with hybrid journals, as evidenced by its indexing in Scopus and RePEc rankings. Economics Bulletin, established in 2001 by AccessEcon, functions as an open-access letters journal for concise notes, comments, and preliminary results across all economics subfields, offering rapid peer-reviewed publication—often within weeks—to facilitate quick dissemination without author fees.^[222] It has published thousands of short papers by 2025, serving as a venue for timely ideas while upholding standards through referee guidelines focused on originality and methodological soundness. In finance, International Journal of Financial Studies, an MDPI open-access journal since 2013, covers financial markets, instruments, policy, and regulation with peer-reviewed articles, though its APC model has drawn scrutiny for potential volume incentives over selectivity in some critiques.^[223] Cogent Economics & Finance, published by Taylor & Francis since 2014, provides open access to multidisciplinary research in econometrics, financial economics, and policy, with APCs and broad scope including economic history and methodology.^[224] Finance Research Open, launched by Elsevier, dedicates itself to advancing finance through open-access publication of theoretical and empirical studies, prioritizing sound research across banking, investments, and corporate finance.^[225] These journals exemplify the spectrum of open-access models in the field, from no-fee diamond options tied to professional societies—which mitigate risks of predatory practices—to APC-based ones, where credibility hinges on publisher reputation and indexing in databases like DOAJ and Scopus.^[4] Diamond models, as in Econometric Society publications, align incentives toward quality over quantity, contrasting with some APC journals where expansion has occasionally diluted rigor, per analyses of economics publishing trends.^[226] Readers should verify current indexing and metrics via sources like RePEc for ongoing assessment.^[227]

Education

Open-access journals in education disseminate peer-reviewed research on pedagogy, curriculum development, educational policy, teacher training, and learning outcomes without subscription fees, often relying on article processing charges or sponsorships. As of 2022, the Directory of Open Access Journals (DOAJ) indexed 1,642 such journals published between 2003 and 2022, reflecting growth driven by demands for equitable access to scholarly work in the field.^[228][4] These publications undergo rigorous peer review to uphold academic standards, with many emphasizing empirical studies and theoretical advancements applicable to K-12, higher education, and lifelong learning contexts.^[4] Indexing in DOAJ requires adherence to criteria such as transparent editorial processes and free online availability of full-text articles under permissive licenses like Creative Commons.^[4] Prominent examples include:

• AERA Open: Launched in 2015 by the American Educational Research Association, this peer-reviewed journal prioritizes rapid dissemination of original empirical and theoretical research across education subfields, including quantitative and qualitative methodologies.^[229][230] It publishes continuously online to accelerate knowledge sharing.^[231]
• International Journal of Educational Technology in Higher Education: Published by SpringerOpen since 2014, it focuses on innovative technology applications for enhancing learning, instructional design, and educational outcomes in postsecondary settings, with a 2022 impact factor of 8.6.^[232][233] Articles explore topics like e-learning systems and data-driven pedagogy.^[234]
• Cogent Education: A Taylor & Francis open-access journal established in 2014, it covers multidisciplinary topics such as educational policy, assessment, leadership, and curriculum innovation through high-quality peer-reviewed articles.^[235][236] It emphasizes global perspectives on teaching practices and institutional reforms.^[237]
• Education Sciences: MDPI's open-access outlet since 2011, it publishes research on diverse educational themes including teacher education, special needs, and interdisciplinary approaches, achieving a 2023 impact factor of 2.6.^[238][239] The journal maintains high visibility through indexing in major databases.^[240]

Game Studies

Game studies encompasses scholarly inquiry into digital games, including their design, cultural impacts, player experiences, and theoretical frameworks such as ludology and narratology. Open-access journals in this field prioritize unrestricted dissemination to foster global collaboration and counter paywall barriers common in humanities and social sciences publishing. These outlets often emphasize peer-reviewed, interdisciplinary work, with many emerging alongside the field's growth since the early 2000s.^[241][242] Prominent open-access journals include:

• Game Studies: Launched in 2001 as the first dedicated open-access journal in the field, this non-profit, cross-disciplinary publication releases issues several times annually via gamestudies.org. It features peer-reviewed articles on games research, spanning topics from narrative analysis to player psychology, without article processing charges. The journal maintains editorial independence and has influenced foundational debates in digital games scholarship.^[241]
• Eludamos: Journal for Computer Game Culture: Established to explore computer games and their cultural dimensions, this peer-reviewed outlet operates under a diamond open-access model (no fees for authors or readers) via Septentrio Academic Publishing at UiT The Arctic University of Norway. Indexed in DOAJ and Scopus, it publishes annually with ISSN 1866-6124 and adheres to CC-BY-4.0 licensing, supporting multilingual submissions on game artifacts, play, and societal intersections.^[243][244]
• Transactions of the Digital Games Research Association (ToDIGRA): Affiliated with the Digital Games Research Association (DiGRA), this quarterly, refereed journal advances multidisciplinary research on games' design, theory, and practice. Fully open access since its inception around 2011, it hosts proceedings and original articles without subscription costs, emphasizing empirical and critical perspectives on digital gaming ecosystems.^[245]
• Press Start: A student-led, peer-reviewed journal initiated in 2014 by the University of Glasgow, focusing on emerging game studies scholarship from undergraduates, postgraduates, and recent graduates. It covers video games, tabletop games, and design across disciplines, providing open access to essays, reviews, and dissertations to democratize entry into academic publishing. No publication fees apply, aligning with its mission to nurture novice researchers.^[246][247]

These journals collectively host thousands of articles, with Game Studies alone archiving over 20 years of content as of 2025, enabling verifiable replication of findings in areas like game mechanics and cultural representation. Selection criteria for inclusion emphasize peer review, indexing in reputable directories like DOAJ, and avoidance of predatory publishers, though the field's relative youth means impact metrics vary.^[241][4]

Geography and Environmental Studies

Open-access journals in geography and environmental studies disseminate peer-reviewed research on spatial dynamics, land use, climate impacts, biodiversity, and human-environmental interactions, often emphasizing empirical data and policy-relevant findings. These publications vary in scope, from physical geography processes to socio-environmental sustainability, and are indexed in directories like DOAJ to verify adherence to open-access standards such as transparent peer review and licensing.^[4] Many operate under creative commons licenses, enabling free reuse while requiring attribution, though author fees (APCs) are common except in diamond models funded by institutions.^[4] Prominent examples include:

• European Journal of Geography: Published by the Association of Greek Geographers, this journal covers geography, spatial analysis, sustainability, built environments, and GIS applications, with issues appearing biannually since 2010.^[248]
• Geographies: An MDPI quarterly journal addressing geomorphology, biogeography, landscape ecology, geomatics, and human-environment interactions, launched in 2021.^[249]
• Geography and Sustainability: Issued by Elsevier, it integrates geographical perspectives on environment, ecosystems, geodata, wellbeing, and sustainability challenges, starting in 2020.^[250]
• Digital Geography and Society: An Elsevier publication exploring spatial technology, digital culture, GIS, big data, and their intersections with human geography, established in 2021.^[251]
• Environmental Health Perspectives: A diamond open-access journal from the National Institute of Environmental Health Sciences (NIEHS), focusing on public health, environmental safety, toxicology, and sciences, with monthly issues since 1972.^[252]
• Environmental Research Letters: Published by IOP Publishing as a fully open-access venue, it prioritizes rapid, concise articles on environmental science, processes, and interdisciplinary policy implications.^[253]
• Frontiers in Environmental Science: A Frontiers Media journal covering environmental toxicology, soil processes, land use systems, water management, and broader ecological dynamics, with continuous online publication.^[254]

These journals contribute to accessible scholarship, though readers should evaluate individual articles for methodological rigor given variability in publisher practices across the open-access landscape.^[4]

Humanities

Open-access journals in the humanities cover disciplines including literature, history, classics, art history, and cultural studies, often prioritizing diamond models—free for both authors and readers—due to limited grant funding compared to sciences, relying instead on library consortia or institutional support to sustain peer-reviewed publishing without article processing charges.^[255] This approach counters risks of predatory practices in fee-based open access, ensuring accessibility while maintaining rigorous editorial standards.^[23] The Open Library of Humanities (OLH), launched in 2015, operates as a nonprofit platform hosting over 30 such journals, funded by global library memberships to promote sustainable, non-commercial dissemination of scholarship.^[255] Prominent examples include:

• Open Library of Humanities: A multidisciplinary journal accepting submissions across humanities fields, emphasizing peer-reviewed articles on topics from literary criticism to historical analysis; it serves as OLH's flagship for broad disciplinary coverage.^[256]
• C21 Literature: Journal of 21st-century Writings: Publishes research on contemporary literature, theory, and cultural contexts, affiliated with the British Association for Contemporary Literary Studies; issues appear annually with thematic focuses like global narratives.^[257]
• 19: Interdisciplinary Studies in the Long Nineteenth Century: Focuses on 19th-century literature, history, and culture across Europe and beyond, integrating interdisciplinary methods; it transitioned to OLH in 2015 for enhanced open access.^[257]
• Orbit: A Research Journal for American Fiction: Devoted to post-1945 American literature, featuring scholarly articles and book reviews; it emphasizes innovative criticism of novels and short fiction.^[257]
• Architectural Histories: Covers the history of architecture and the built environment, sponsored by the European Architectural History Network; articles span global case studies from antiquity to modernity.^[257]
• Theoretical Roman Archaeology Journal (TRAJ): Examines Roman archaeology through theoretical lenses, including postcolonial and material culture approaches; it publishes conference proceedings and standalone papers annually.^[257]
• The Comics Grid: Journal of Comics Scholarship: Explores comics as a medium in cultural and literary studies, with multidisciplinary contributions on narrative, visuals, and history; founded in 2010.^[257]
• Open Cultural Studies: An international journal addressing cultural phenomena across humanities and social sciences, including media, identity, and globalization; it uses a double-blind peer-review process.^[258]

These journals demonstrate the viability of community-funded open access in humanities, where readership metrics and citation impacts often lag behind subscription models but prioritize long-term preservation and equity over profit-driven metrics.^[255] Selection criteria for inclusion emphasize peer-reviewed status, DOAJ indexing where applicable, and avoidance of high-APC models prevalent in less vetted outlets.^[4]

Language and Linguistics

Open-access journals in language and linguistics primarily disseminate peer-reviewed research on theoretical frameworks, empirical analyses of language structures, sociolinguistic patterns, psycholinguistic processes, and applied aspects such as language acquisition and typology, without paywalls for readers. The discipline has embraced diamond open-access models extensively, where no fees are charged to authors or readers, often supported by academic institutions, societies, or consortia; this contrasts with gold open-access alternatives reliant on article processing charges. As of November 2024, the Directory of Open Access Journals indexes 906 linguistics journals, the majority diamond open access, reflecting community-driven initiatives to prioritize accessibility over commercial interests.^[259] These journals emerged partly in response to dissatisfaction with high subscription costs and vendor lock-in at legacy publishers, exemplified by the 2015 LingOA campaign, where editors resigned from Elsevier's Lingua to establish independent open-access alternatives emphasizing fair governance and transparency.^[260] The Open Access Linguistics (OALing) directory catalogs over 80 peer-reviewed platinum journals focused on general, descriptive, and theoretical linguistics, open to global submissions and covering subfields like phonology, syntax, and semantics.^[261] Prominent examples include:

• Glossa: a journal of general linguistics, a diamond open-access publication owned and governed by the linguistics community via the Open Library of Humanities platform, featuring rigorous peer review for articles, squibs, and replication studies across all linguistic domains; launched in 2016 as a direct successor to Lingua, it maintains high standards without author fees.^[262][263]
• Biolinguistics, an online-only diamond journal exploring the biological underpinnings of language, including generative theory, evolutionary biology, genetics, and cognitive mechanisms of acquisition; published biannually since 2007 by PsychOpen (a Leibniz Institute service), it bridges linguistics with experimental sciences like neurolinguistics and is indexed in DOAJ and Scopus.^{[264][265][266]}
• Journal of Linguistics, a fully open-access journal covering theoretical linguistics across phonetics, morphology, syntax, and pragmatics, with preference for original research advancing formal models; transitioned to open access in 2021 under Cambridge University Press, supported by read-and-publish agreements that eliminate author charges in participating institutions.^[267]

Specialized diamond journals abound, such as Acta Linguistica Asiatica for Asian languages and translation studies, and Anglophonia for English linguistics from a French perspective, both peer-reviewed and multilingual in scope.^[261] Broader language studies outlets like Languages (MDPI) offer gold open-access coverage of multilingualism and applied topics but require article processing charges averaging 2000 Swiss francs.^[268] This diversity ensures comprehensive coverage, though researchers must verify indexing in databases like Scopus or Web of Science for credibility, as not all open-access venues undergo equivalent scrutiny.^[266]

Law

Open-access journals in law disseminate legal scholarship without paywalls, typically through diamond open access (no fees to readers or authors) or gold open access funded by article processing charges (APCs). As of October 2024, the Directory of Open Access Journals (DOAJ) indexes approximately 860 journals under the law category, though this includes multidisciplinary and niche publications, with rigorous peer-reviewed options emphasizing empirical legal studies, comparative law, and policy analysis.^[269] These journals counter traditional subscription models dominated by commercial publishers, promoting wider access amid critiques of high costs in legal publishing.^[4] Notable examples include the Utrecht Law Review, a diamond open-access journal published by Utrecht University since 2005, specializing in cross-border legal research, European law, and comparative methodologies with double-blind peer review. It publishes biannually and is indexed in Scopus and DOAJ.^[270] Laws, published bimonthly by MDPI since 2012, covers legal systems, theory, institutions, and interdisciplinary applications like environmental and health law, employing anonymous peer review with an average of six weeks from submission to publication; it charges APCs around CHF 1800 but waives for some authors.^[271][272] The Journal of Legal Analysis, issued by Harvard Law School and Oxford University Press since 2009, applies economic and empirical methods to legal questions, operating as diamond open access with rigorous peer review; it ceased regular publication in 2020 but archives remain accessible.^[273] Journal of Open Access to Law (JOAL), launched by Cornell Law School in 2024, focuses on legal information science, open-access policies in law, and publishing innovations, featuring peer-reviewed articles on topics like AI in legal data and access barriers.^[274] The Journal of Law and the Biosciences, a Duke University and Stanford initiative since 2014, is fully open access and peer-reviewed, addressing bioethics, biotechnology regulation, and intersections of law with life sciences, funded partly by institutional support to avoid APC dependency.^[275] These journals prioritize verifiable methodologies over ideological advocacy, though selection of submissions may reflect prevailing academic perspectives in legal scholarship. Researchers should verify indexing in DOAJ or Scopus for credibility, as open access does not guarantee quality absent peer review.^[4]

Library and Information Science

Open-access journals in library and information science facilitate unrestricted dissemination of peer-reviewed research on topics including cataloging, digital preservation, information retrieval, and evidence-based librarianship. These publications, often indexed in the Directory of Open Access Journals (DOAJ), number over 150 globally as of recent analyses, originating from diverse countries and emphasizing practical and theoretical advancements in the field.^[4][276] Quality control varies, with DOAJ certification indicating adherence to transparent peer-review and licensing standards, though some journals face scrutiny for editorial rigor. Notable peer-reviewed open-access journals in this discipline include: These journals typically operate under Creative Commons licenses, promoting reuse while requiring attribution, and many publish articles continuously or in themed issues to address emerging challenges like data curation and open scholarship.^[4] Subscription-free access has increased citation rates for LIS research, though sustainability relies on institutional funding or article processing charges averaging $1,000–$2,000.^[279] Researchers should verify current indexing and predatory status via tools like DOAJ or Think. Check before submission.^[4]

Music

Open-access journals in music scholarship encompass peer-reviewed publications across subdisciplines such as music theory, ethnomusicology, historical musicology, and music education, enabling unrestricted access to research outputs without subscription barriers. As of April 2024, the Directory of Open Access Journals (DOAJ) indexes 89 titles categorized under music and books on music, reflecting growth driven by digital platforms and institutional repositories.^[280] Many of these journals operate without article processing charges, prioritizing diamond open access to support global dissemination, though quality varies and indexing in DOAJ serves as a baseline indicator of adherence to open-access standards.^[281] Pioneering examples include Music Theory Online, established in 1993 by the Society for Music Theory as a fully open-access, peer-reviewed electronic journal dedicated to research, criticism, and analysis in music theory and cognate fields.^[282] It publishes original articles, reviews, and multimedia content, with continuous operation underscoring its role in transitioning music scholarship to digital formats.^[283] Similarly, Music & Science, launched by Sage in partnership with the Society for Education, Music and Psychology Research, focuses on empirical investigations into music cognition, perception, performance, and interdisciplinary applications since its inception around 2015.^[284] In specialized areas, Musical Offerings provides peer-reviewed content on musicology, ethnomusicology, and church music history, emphasizing historical and analytical perspectives.^[285] Music & Minorities examines ethnomusicological topics related to minority cultures, identity, and preservation efforts.^[286] European contributions feature prominently, such as Muzyka, a Polish journal covering music history, theory, and ethnomusicology with a focus on Central European contexts.^[287] Disciplinary repositories like musiconn.publish further support open access by archiving musicological works, particularly from German institutions.^[280] Comprehensive directories, such as the List of Open-Access Music Journals, catalog 216 active peer-reviewed titles as of December 2024, with over half originating in Europe and spanning categories from general musicology to technology and popular music studies.^[281] These resources highlight the field's shift toward inclusive access, though adoption remains uneven compared to subscription models in established societies.^[288]

Philosophy

Open access journals in philosophy facilitate unrestricted access to peer-reviewed scholarship, addressing barriers posed by subscription-based models prevalent in the discipline. These publications often emphasize rigorous double-anonymous peer review and cover diverse subfields, from metaphysics and epistemology to ethics and philosophy of mind. As of 2024, directories like the Directory of Open Access Journals (DOAJ) index over 100 philosophy-specific open access titles, though quality varies, with diamond open access models (no author fees) preferred in academia to avoid pay-to-publish biases.^[4][289] Prominent examples include:

• Ergo: An Open Access Journal of Philosophy, launched in 2014 by the University of Michigan Library, accepts submissions on all philosophical topics using double-anonymous review; it imposes no article processing charges (APCs) and has published over 550 articles by 2025.^[290]
• Journal of Modern Philosophy, an open access venue since 2022 focusing on philosophy from the 16th to early 20th centuries, employs rigorous peer review and diamond access without APCs.^[291]
• Open Philosophy, published by De Gruyter since 2018, covers all areas of philosophy with peer-reviewed articles available under a Creative Commons license, though it charges APCs around €1,000–2,000.^[292]
• Argumenta, a double-anonymous peer-reviewed journal since 2015 specializing in philosophy of language, mind, and cognition, operates on a diamond open access basis with no fees.^[293]
• Krisis: Journal for Contemporary Philosophy, an independent open access platform since 1988 (relaunched digitally), publishes peer-reviewed articles on social, cultural, and political philosophy without APCs.^[294]
• Journal of the American Philosophical Association, transitioning to full open access for articles accepted after July 9, 2024, under Cambridge University Press, with hybrid prior content; it maintains high standards via the American Philosophical Association.^[295]

These journals contribute to broader accessibility, though philosophers often supplement with green open access via repositories like PhilPapers, which hosts over 2.9 million entries as of 2024. Adoption remains uneven due to entrenched subscription traditions and concerns over predatory publishing.^[296][297]

Political Science

Open-access journals in political science facilitate unrestricted access to scholarly work on governance structures, electoral processes, international relations, public policy, and theoretical frameworks of power dynamics. These publications typically rely on author fees or institutional support to cover peer-review and dissemination costs, contrasting with traditional subscription models that limit readership. Indexed in directories like the Directory of Open Access Journals (DOAJ), reputable open-access outlets in the field maintain rigorous peer review to uphold academic standards, though variability exists across titles, with some achieving higher citation impacts through empirical rigor and methodological transparency.^[4] Key examples include Research & Politics, launched in 2014 by SAGE Publishing, which emphasizes succinct, data-driven articles on core political phenomena such as voting behavior and institutional design, achieving a SCImago Journal Rank (SJR) of 1.14 as of recent assessments.^[298][299] Frontiers in Political Science, initiated in 2021 by Frontiers Media, adopts an interactive peer-review model to explore political systems, conflict resolution, and policy implementation across local to global scales, with a 2023 CiteScore of 2.9 and Impact Factor of 2.3.^[300][301] Politics and Governance, established in 2013 by Cogitatio Press, publishes multidisciplinary studies on political processes, European integration, and governance innovations, prioritizing open data and replicable findings.^[302][303] The Journal of Deliberative Democracy, evolved from the Journal of Public Deliberation founded in 2005 and fully open-access since its relaunch, centers on participatory decision-making, discourse ethics, and empirical evaluations of deliberative experiments, fostering debate on democratic legitimacy without paywalls.^[304] These journals contribute to broader accessibility in political science, where empirical evidence from randomized trials and comparative case studies increasingly informs submissions, though readers should verify methodological soundness given occasional critiques of APC-driven incentives potentially favoring volume over depth in less-established open-access venues.^[308]

Social Science

Open-access journals in social sciences encompass peer-reviewed publications providing unrestricted access to research across disciplines such as sociology, anthropology, psychology, and economics, often indexed in directories like the Directory of Open Access Journals (DOAJ).^[4] These journals facilitate broader dissemination of empirical studies and theoretical analyses, with many adopting gold open access models that may involve article processing charges (APCs) covered by authors or institutions.^[4] Reputable examples are typically affiliated with established publishers and maintain rigorous peer review, though the field includes both diamond open access (no fees) and APC-based options.^[309] Notable broad-scope journals include:

• SAGE Open: Launched in 2011 by SAGE Publications, this peer-reviewed gold open access journal publishes original research and reviews in social and behavioral sciences, including interdisciplinary topics, with an emphasis on innovative methodologies.^[310]
• Social Sciences (MDPI): Established in 2012 by MDPI, an international peer-reviewed open access journal covering anthropology, economics, psychology, social psychology, and sociology, featuring rapid peer review and APCs around 1800 CHF.^[309]
• Social Sciences & Humanities Open: Published by Elsevier since 2019, this fully open access journal addresses social sciences, economics, and overlapping humanities areas through empirical and theoretical contributions, with APCs funded via institutional agreements or authors.^[311]

Specialized yet interdisciplinary outlets within social sciences, such as Forum: Qualitative Social Research (founded 2000, diamond open access, focusing on qualitative methods in sociology and related fields), exemplify diamond models without publication fees, promoting accessibility for non-funded researchers. DOAJ indexes over 1,000 social sciences journals as of 2023, reflecting growth in open access but requiring evaluation for quality amid varying editorial standards.^[312]

Interdisciplinary and Megajournals

Megajournals and Cross-Disciplinary Publications

Megajournals constitute a subset of open-access publications distinguished by their expansive, multidisciplinary scope and peer-review criteria limited to scientific validity, methodological soundness, and reproducibility, eschewing evaluations of novelty, impact, or audience interest.^[313] This approach facilitates high-volume dissemination of technically rigorous research across fields, supported primarily by article processing charges (APCs) rather than subscriptions.^[314] Originating in the mid-2000s amid the expansion of digital platforms and open-access mandates, megajournals have published millions of articles collectively, though growth has slowed for some titles post-2017 due to market saturation and varying acceptance rates.^[313] Cross-disciplinary publications overlap with megajournals but may include specialized open-access venues spanning multiple domains without the same emphasis on scale; however, megajournals exemplify the model through their inclusive editorial policies.^[315] Key examples include:

• PLOS ONE, launched December 20, 2006, by the Public Library of Science (PLOS), accepts submissions from all scientific disciplines, reviewing solely for soundness and ethical compliance.^{[316] [317]} It pioneered the format, peaking at over 30,000 articles annually before stabilizing.^[313]
• Scientific Reports, established in 2011 by Nature Portfolio (part of Springer Nature), spans biological, physical, and engineering sciences, prioritizing validity over subjective merit.^{[318] [319]} By 2016, it approached becoming the world's largest journal by output, with annual publications exceeding 20,000.^[320]
• PeerJ, initiated in June 2012 with first articles in February 2013 by PeerJ Inc. (acquired by Taylor & Francis in 2024), focuses on biological, medical, and environmental sciences while employing a membership or APC model for broad accessibility.^{[321] [322]} It emphasizes rigorous peer review for reliability across interdisciplinary topics.^[323]
• Heliyon, started in 2015 by Elsevier (under Cell Press), covers physical, life, social, and medical sciences, accepting valid research irrespective of perceived importance, with an APC of $2,270.^{[324] [325]} In 2024, it faced temporary suspension of new indexing in Web of Science amid quality reviews.^[326]

Other notable megajournals include BMJ Open (2011, BMJ, clinical and public health focus) and ACS Omega (2016, American Chemical Society, chemistry and allied fields), which similarly prioritize volume and soundness in cross-disciplinary contexts.^[327] These platforms have democratized access but raised concerns over diluted selectivity, with empirical analyses showing comparable citation impacts to selective journals in some cases, though reliant on robust post-publication scrutiny.^[313]