Free UI Sprites and Game Interface Packs
Interface art is where hobby projects most often give themselves away, and it's also the cheapest thing to fix. Kenney's UI packs are CC0 and complete, meaning the button, its pressed state, the panel behind it, and the slider all come from one hand. Take a whole pack rather than the best individual pieces from several, because mismatched corner radii and border weights are obvious even to players who can't name what's wrong.
Everything here is free to download from the source site. These results come from Kenney. Licences vary by file and are shown on each card. Nothing is hosted by us, and every link goes to the original page so you get the current version and the real licence terms.
Fantasy UI BordersCC0
Hexagon BuildingsCC0
Isometric Tiles BuildingsCC0
Monster Builder PackCC0
Pixel UI PackCC0
Platformer Art BuildingsCC0
UI PackCC0
UI Pack - AdventureCC0
UI Pack - Pixel AdventureCC0
UI Pack (RPG Expansion)CC0
UI Pack - Sci-FiCC0Search all sprites in the live asset library →
Using these sprites in a game
Pack sprites into an atlas before shipping. One texture with everything on it means one GPU upload and one draw call for your whole interface, instead of one per image, and that's the difference between a smooth 2D game and a stuttering one on mobile.
Keep the source art at its authored resolution and scale in-engine rather than resizing the files, especially for pixel art, where any resampling that isn't a clean integer multiple destroys the edges. Set your texture filtering to nearest for pixel art too, or everything comes out blurry.
For engine choices in 2D, see Phaser vs Defold and Construct vs GDevelop.
Licences, briefly
CC0 means public domain: use it commercially, modify it, ship it, no credit required. That covers everything from Kenney, Quaternius, KayKit, Poly Haven, and AmbientCG.
Freesound and OpenGameArt host a mix. Some files are CC0, others are CC-BY (credit required) or CC-BY-SA (credit required and derivatives must carry the same licence, which is a real constraint on a commercial game). The licence is set per file by whoever uploaded it, so check the source page before you ship.
The complete guide to game asset licences covers what each one actually requires and where teams usually get it wrong.
More free sprites
Free Platformer Sprites and Tilesets · Free Game Tilesets · Free Game Icons
Or search every source at once, and see the complete guide to free game assets for the full picture on where this art comes from and how to use it.