Sprite Foundry — Free Online Spritesheet Builder for Indie Game Developers
Sprite Foundry is a free, browser-based spritesheet builder designed for indie game developers,
pixel artists, and game asset creators. Pack multiple sprites into a single sheet, extract every
frame from an animated GIF, slice an existing spritesheet into individual frames, and preview
animations in real time — all without uploading anything to a server.
Features
- Pack sprites into a spritesheet with custom grid layout (columns, rows, padding, spacing)
- Extract frames from animated GIFs with correct disposal method handling
- Import an existing spritesheet and slice it into individual frames
- Real-time animation preview with FPS adjustable from 1 to 60
- Onion skin mode: visualize previous and next frames with color-coded ghosting
- Zoom from 25% to 800% for pixel-perfect inspection
- Fixed output dimensions (e.g., 512x512, 1024x1024) or automatic sizing
- Pixel-perfect rendering — no antialiasing, no blur
- Export as PNG spritesheet, animated GIF, or JSON metadata
- JSON output compatible with Phaser, Godot, Unity, GameMaker, Construct
- Optional transparent pixel trimming per frame
- Drag and drop frame reordering
Who is it for
Indie game developers working with 2D engines like Godot, Unity, Phaser, GameMaker Studio,
Construct, Defold, and LÖVE. Pixel artists who need to organize their sprites into engine-ready
formats. Animators who want to preview GIF animations frame by frame. Retro game enthusiasts
extracting sprites from classic games for personal projects.
Privacy
Everything runs locally in your browser. No files are uploaded to any server. No signup, no
login, no ads, no tracking cookies. Your sprites stay on your device.
Common use cases
- Convert an animated GIF into a spritesheet for use in a game engine
- Unpack an existing spritesheet to edit individual frames in Aseprite or Photoshop
- Combine separate PNG frames into a single spritesheet with JSON metadata
- Preview how a sprite animation will look before shipping it
- Generate a spritesheet at a fixed resolution to match texture atlas requirements