Splenda /ˈsplɛndə/ is a global brand of sugar substitutes and reduced-calorie food products. While the company is known for its original formulation containing sucralose, it also manufactures items using natural sweeteners such as stevia, monk fruit and allulose. It is owned by the American company Heartland Food Products Group. The high-intensity sweetener ingredient sucralose used in Splenda Original is manufactured by the British company Tate & Lyle.

Sucralose was discovered by Tate & Lyle and researchers at Queen Elizabeth College, University of London, in 1976. While researching new insecticides, Shashikant Phadnis at Queen Elizabeth College misheard the instruction of his advisor Leslie Hough to "test" the chemical as "taste," due to his misunderstanding of the foreign accent, so he accidentally tasted the chemical and found it to be extremely sweet. Tate & Lyle subsequently developed sucralose-based Splenda products in partnership with Johnson & Johnson subsidiary McNeil Nutritionals, LLC. The Splenda brand was transferred to Heartland Food Products Group after its purchase of the line with investor Centerbridge Partners in 2015.

Since its approval by the United States government in 1998 and introduction there in 1999, sucralose has overtaken Equal in the $1.5-billion artificial sweetener market, holding a 62% market share. Splenda sales were $212 million in 2006 in the U.S., while Equal's totaled $48.7 million. According to a 2012 article in The New Zealand Herald, it is "the category leader in table-top sweetener in the U.S. Splenda is the most commonly used sugar substitute, with tens of millions of U.S. consumers per year (as of 2025).

Splenda is available in a variety of products:

The energy content of a single-serving (1 g packet) of Splenda is 3.36 kcal, which is 31% of a single-serving (2.8 g packet) of granulated sugar (10.8 kcal). In the United States, it is legally labelled "zero calories"; U.S. FDA regulations allow this "if the food contains fewer than 5 Calories per reference amount customarily consumed and per labeled serving". Splenda powder consists of predominantly fillers as bulking agents – dextrose and maltodextrin. Sucralose content is about 1.1% and remainder is bulking agents.

Unlike other artificial sweeteners, sucralose is heat-stable up to 450 °F (232 °C), so Splenda can be used as a replacement for table sugar in cooking and baking, and there are Splenda products packaged specifically for this purpose. In product testing by Cook's Illustrated, the major drawback to cooking with Splenda was found to be that it does not produce the browning or caramelization the way table sugar does. However, Cook's Illustrated also found that desserts baked with Splenda were "lacking the artificial flavors that just about every other sugar substitute brings with it."

Splenda usually contains 95% dextrose (D-glucose) and maltodextrin (by volume) which the body readily metabolizes, combined with a small amount of mostly indigestible sucralose. Sucralose is made by replacing three select hydrogen-oxygen groups on sucrose (table sugar) molecules with three chlorine atoms. The tightly bound chlorine atoms create a molecular structure that is stable under intense conditions. Sucralose itself is recognized as safe to ingest as a diabetic sugar substitute, but the sugars or other carbohydrates used as bulking agents in Splenda products should be evaluated individually.

The acceptable daily intake (ADI) for sucralose is 5 mg per kilogram of body weight per day according to the U.S. Food and Drug Administration (FDA), and 15 mg/kg/day according to the European Food Safety Authority (EFSA). These values represent the amount that can be consumed daily over a lifetime without appreciable health risk.