Keyframe.it.com

Keyframe.it is a free 2D skeletal animation editor that runs entirely in your browser. You rig artwork with bones (FK + IK), deform it with auto-traced weighted meshes, and animate on a keyframe dope sheet with a full curve editor. Spring physics adds automatic secondary motion  hair, tails, cloth, smoke  and bakes to keyframes on export.

Exports are Spine-compatible bundles (3.8 / 4.2, JSON or binary .skel + atlas + packed PNG) that load directly in pixi-spine and spine-pixi-v8, plus GIF, sprite sheet, and video. It imports existing Spine exports and PSDs (layers become parts).

It's built especially for slot & casino game art: one-click idle/win/drop/destroy animation packs, a win-FX library (coin showers, shockwaves, light rays, payline streaks), and slot-cell canvas guides. A built-in image editor and sheet slicer mean you never round-trip to Photoshop, and a 150+ method scripting API lets AI agents drive the whole editor. Work autosaves locally; nothing is uploaded.