Free, no subscription

Rig it. Key it.
Ship it.

A 2D skeletal animation editor. Build bone rigs, key them on a timeline, export video or sprite sheets.

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SpineBones

120FPS ceiling

300Frame timeline

3Export formats

2Desktop platforms

The SpineBones editor showing a bone list, character canvas, bone properties, and a keyframe timeline

Bone hierarchy, slots, properties, and the keyframe timeline in a single window.

A full rig pipeline in one window

No plugins to install, no per-seat licence, no cloud round trip.

A hooded character with bone joints placed along the arms, legs, and torso

Bones and hierarchies

Draw bone chains straight on the canvas, re-parent without the rig jumping, and group what belongs together. IK is there for the chains that need it.

Keyframes stacked across several bone tracks in the SpineBones timeline, with the playhead to their right

Timeline and keyframes

Insert, drag, multi-select, copy, and loop keys. Set easing per key, and drop in an audio track when the timing has to land on a beat.

Slots and attachments

Bind PNG, JPG, SVG, or WebP art to a bone, stack several attachments per slot, and swap them frame by frame for sprite work.

Mesh deformation

Turn any attachment into a mesh, push vertices around on the canvas, and key the deformation so cloth and hair bend instead of sliding.

Onion skin

Ghost the poses on either side of the playhead to check arcs and spacing before they turn into a pop.

Previous pose Next pose

A viewport that matches the export

The 16:9 preview is the frame you ship. Pan and zoom the camera freely, then play the whole thing back at up to 120 frames per second.

An illustrated character posed inside the SpineBones export viewport

Two modes. One rig.

SETUP holds the base pose. ANIMATE holds the keys. Editing one does not wreck the other.

Rigging a character from scratch

Rig

In SETUP, build the bone chain, hang art off slots, and align every attachment to its bone. The timeline stays out of your way.
Animate

Switch to ANIMATE and key position, rotation, and scale. Fade attachments, bend meshes, let IK handle the arms and legs.
Refine

Scrub, loop, and play at the real frame rate. Turn on onion skin to read the arcs, and load audio when the timing has to match sound.
Export

Write out a WebM, a PNG sequence, or a sprite sheet. Or save an .sbn package and pick the work back up on another machine.

MCP Bridge

Drive the editor from an AI agent

The MCP bridge exposes the rig, the timeline, and the exporter to Claude and any other MCP client.

Create bones, slots, and keyframes from plain instructions
Rescale a whole animation to a new frame rate in one call
Kick off exports from a script instead of the menu bar

Four ways out

Web, compositor, game engine, or back into SpineBones tomorrow.

.webm

Video

The full animation rendered frame by frame, background image included when one is active.

.png

Frame sequence

Transparent frames zipped up, ready to drop into After Effects, Resolve, or any compositor.

.zip

Sprite sheet

A packed sheet with its atlas data, sized for game engines and 2D frameworks.

.sbn

Project

Bones, slots, keys, and every bundled image in one portable file. Legacy .json projects open too.

Hands stay on the keyboard

Every tool, mode, and timeline move is one key away.

Tools

Q: Pose
B: Bone
M: Move
R: Rotate
S: Scale

Modes

W: SETUP mode
E: ANIMATE mode
O: Onion skin
⌘B: Bone indicators
Esc: Clear selection

Timeline

Space: Play or pause
K: Insert keyframe
←: Previous frame
→: Next frame
X: Delete hovered key

File

⌘Z: Undo
⌘⇧Z: Redo
⌘S: Save
⌘O: Open
⌘N: New project

Start animating today

Free to download. No account, no licence key, no trial timer.