SpriteFrame

Your game character can stand still. Now it has to walk, and every stage of the step needs a slightly different picture, each one drawn by hand. SpriteFrame starts from one picture of the character and an action, picked from presets like Walk or described in your own words. AI turns this into a short video, then cuts it into the number of frames you choose with the background removed.

The homepage notes that AI results can need manual cleanup. In the frame editor you delete unwanted poses and erase leftover background around the outline, and parts that were cut away can be restored. Loop suggestions mark where a walk can repeat without a visible jump. A scene preview lets you steer the character with the arrow keys before export.

Frames you already have go through the same editor without an account. The PNG tool takes up to 120 images, sorts numbered names so walk_2 comes before walk_10, and keeps their transparency. The video tool cuts frames from an MP4 clip of up to 30 seconds. Both run in the browser, and the site says only the AI features upload files.

Games usually load animation from a sprite sheet, one large image with every frame laid out in a grid. Exports come as a ZIP with that sheet or separate PNG frames, plus a JSON file with frame order and timing. Slicing the sheet and setting up playback happen in the game engine.