Zig is an imperative, general-purpose, statically typed, compiled system programming language designed by Andrew Kelley. It is free and open-source software, released under an MIT License.

A major goal of the language is to improve on the C language, with the intent of being even smaller and simpler to program in, while offering more functionality. The improvements in language simplicity relate to flow control, function calls, library imports, variable declaration and Unicode support. Further, the language makes no use of macros or preprocessor instructions. Features adopted from modern languages include the addition of compile time generic programming data types, allowing functions to work on a variety of data, along with a small set of new compiler directives to allow access to the information about those types using reflective programming (reflection). Like C, Zig omits garbage collection, and has manual memory management. To help eliminate the potential errors that arise in such systems, it includes option types, a simple syntax for using them, and a unit testing framework built into the language. Zig has many features for low-level programming, notably packed structs (structs without padding between fields), arbitrary-width integers and multiple pointer types.

The main drawback of the system is that, although Zig has a growing community, as of 2025, it remains a new language with areas for improvement in maturity, ecosystem and tooling. Also the learning curve for Zig can be steep, especially for those unfamiliar with low-level programming concepts. The availability of learning resources is limited for complex use cases, though this is gradually improving as interest and adoption increase. Other challenges mentioned by the reviewers are interoperability with other languages (extra effort to manage data marshaling and communication is required), as well as manual memory deallocation (disregarding proper memory management results directly in memory leaks).

The development is funded by the Zig Software Foundation (ZSF), a non-profit corporation with Andrew Kelley as president, which accepts donations and hires multiple full-time employees. Zig has very active contributor community, and is still in its early stages of development. Despite this, a Stack Overflow survey in 2024 found that Zig software developers earn salaries of $103,000 USD per year on average, making it one of the best-paying programming languages. However, only 0.83% reported they were proficient in Zig.

The primary goal of Zig is to be a better solution to the sorts of tasks that are currently solved with C. A primary concern in that respect is readability; Zig attempts to use existing concepts and syntax wherever possible, avoiding the addition of different syntax for similar concepts. Further, it is designed for "robustness, optimality and maintainability", including a variety of features to improve safety, optimization, and testing. The small and simple syntax is an important part of the maintenance, as it is a goal of the language to allow maintainers to debug the code without having to learn the intricacies of a language they might not be familiar with. Even with these changes, Zig can compile into and against existing C code; C headers can be included in a Zig project and their functions called, and Zig code can be linked into C projects by including the compiler-built headers.

In Zig, if something calls a function, it looks like a function call; if it doesn’t, it doesn’t look like a function call. If it can raise an error, it is explicit in the syntax. Error handling is handled through error types and can be handled with catch or try. Zig has a more conservative extension of the type system, supporting compile time generics and accommodating a form of duck typing with the comptime directive.

One of the primary sources of bugs in C programs is the memory management system, based on malloc. malloc sets aside a block of memory for use in the code and returns a reference to that memory as a pointer. There is no system to ensure that memory is released when the program no longer needs it, which can lead to programs using up all available memory, a memory leak. More common is a dangling pointer that does not refer to a properly allocated memory object.

A common solution to these problems is a garbage collector (GC), which examines the program for pointers to previously allocated memory, and removing any blocks that no longer have anything pointing to them. Although this greatly reduces, or even eliminates, memory errors, types of GC systems may have unpredictable performance that makes them unsuited to real-time computing and systems programming. Another solution is automatic reference counting (ARC), which implements the same basic concept of identifying blocks of disused memory, but does so at pointer creation and destruction time by maintaining the number of pointers to a block, meaning there is no need to perform exhaustive pointer searches, which are rendered unnecessary at the cost of adding reference counter adjustment overhead to every pointer creation and destruction operation.