Freedom251 › 2D Character Animation Software

SpriteForge

Free plan Web

What SpriteForge is

SpriteForge is a free, open-source browser editor for rigged 2D sprite animation. It runs locally without an account, server, or upload pipeline, keeping projects and images on the user's machine. Users can import PNG or JPG images, including TexturePacker-style sprite sheets, build a parent-child bone rig, pose characters, and animate them on a timeline. The timeline includes keyframes, copy and paste, duplication, easing presets, curve display, undo and redo, and two-bone inverse kinematics. Mesh attachments use GPU skinning and automatic weight recomputation. Editable projects use the .sfproj format and autosave in browser localStorage. Exports include Spine-style JSON, atlas and PNG files, a standalone runtime.html player, and MP4 previews encoded with H.264 through ffmpeg.wasm. Exported Spine JSON is intended for compatible runtimes including Phaser, PixiJS, Unity, Godot, and custom runtimes. SpriteForge is an early release, with several advanced animation features still in progress. Spine bundle import is partial, and mobile or touch editing is unsupported. Desktop support covers the latest two versions of Chrome, Firefox, Safari, and Edge.

Who it suits

SpriteForge is intended for small teams, game jam projects, tool hackers, and people seeking a lightweight 2D rigging workflow. It may suit users who want local browser-based editing and Spine-compatible exports.

What it does well

Runs locally without accounts or uploads.
Supports PNG, JPG, and sprite sheet imports.
Exports Spine-style JSON, atlas, and PNG bundles.
Includes timeline editing and two-bone inverse kinematics.

What to know first

Mobile and touch editing are unsupported.
Spine bundle import omits several types of data.
Some advanced animation features remain in progress.
MP4 export may be slow on first use.

Limits

Spine 4.x bundle import is partial and omits constraints, non-default skins, FFD, events, draw order, and linked meshes, with warnings. Several advanced tools remain in progress; mobile and touch editing are unsupported.

Getting started

Open the SpriteForge website in a supported desktop browser.
Import PNG or JPG images, or a TexturePacker-style sprite sheet.
Build a parent-child bone rig and pose the character.
Animate with keyframes on the timeline.
Save the editable project as an .sfproj file or export a runtime bundle.

Verdict

SpriteForge provides a local browser workflow for rigging and animating 2D sprites, with several export options. Its early status, partial Spine import, and unsupported mobile editing set clear boundaries.

Questions

Is SpriteForge free?

Yes. It is free and open source under the MIT license.

Does SpriteForge require an account or upload?

No. It runs in a browser tab without an account, server, or upload pipeline, and keeps project data and images on the user's machine.

Which platforms and browsers does it support?

It is a web editor with desktop support for the latest two versions of Chrome, Firefox, Safari, and Edge. Mobile and touch editing are unsupported.

What does SpriteForge export?

It exports Spine-style JSON, atlas and PNG bundles, a standalone runtime.html player, and MP4 previews.

Which runtimes can use its exports?

Exports are intended for compatible Spine-style runtimes, including Phaser, PixiJS, Unity, Godot, and custom runtimes.

Can it import Spine bundles?

Spine 4.x bundle import is partial and may omit constraints, non-default skins, FFD, events, draw order, and linked meshes.

Facts from SpriteForge's own pages

Animation features: The editor includes a timeline with keyframes, easing, curve previews, undo and redo, and two-bone inverse kinematics. · github.com, 9 Oct 2026
Browser support: The specification lists desktop support for the latest two versions of Chrome, Firefox, Safari, and Edge, and says mobile/touch editing is unsupported. · github.com, 9 Oct 2026
Development status: The repository describes SpriteForge as an early open-source release and says several advanced animation features are still in progress. · github.com, 8 Oct 2026
Export formats: Exports include Spine 4.x-style JSON, atlas and PNG files, a standalone runtime.html player, and MP4 previews. · github.com, 9 Oct 2026
Exports: SpriteForge exports Spine-style JSON, atlas, and PNG bundles, plus MP4 previews using H.264 via ffmpeg.wasm. · github.com, 8 Oct 2026
Feature status: The project describes itself as an early open-source release, and says some advanced animation features remain in progress. · github.com, 9 Oct 2026
How it works: Users import images, create a bone rig, keyframe animation, and export a Spine-compatible JSON, atlas, and PNG bundle. · github.com, 9 Oct 2026
Image and mesh features: It supports PNG/JPG insertion, TexturePacker-style sprite sheet import, mesh attachments with GPU skinning, and automatic weight recomputation. · github.com, 8 Oct 2026
Image import: SpriteForge supports PNG and JPG images and TexturePacker-style sprite sheet import. · github.com, 9 Oct 2026
Import compatibility: Spine bundle import is partial and may omit constraints, non-default skins, FFD, events, draw order, and linked meshes, with warnings. · github.com, 9 Oct 2026
Import limits: Spine 4.x bundle import is partial and omits constraints, non-default skins, FFD, events, draw order, and linked meshes, with warnings. · github.com, 8 Oct 2026
Integrations: The specification says exported Spine JSON can be used with runtimes including Phaser, PixiJS, Unity, Godot, and custom runtimes. · github.com, 9 Oct 2026
Intended users: The project is aimed at small teams, game-jam projects, tool hackers, and people seeking a lightweight 2D rigging workflow. · github.com, 9 Oct 2026
License: The repository lists an MIT license. · github.com, 9 Oct 2026
Local operation: The editor runs in the browser, with no account, server, or upload pipeline; project data and images stay on the user's machine. · github.com, 9 Oct 2026
Local use: The project says it runs in a browser tab without an account, server, or upload pipeline, keeping projects and images on the user's machine. · github.com, 8 Oct 2026
MP4 limitation: MP4 export uses ffmpeg.wasm, whose large bundle can make the first export slow; GIF export is not supported. · github.com, 9 Oct 2026
Notable missing features: Brush-based weight painting, full mesh edge split/merge tools, full FFD workflow, and multi-bone and path inverse kinematics are listed as incomplete. · github.com, 8 Oct 2026
Privacy and telemetry: The repository describes its privacy model as local-first, with no telemetry or uploads. · github.com, 8 Oct 2026
Project files: Editable projects use the .sfproj format, which stores project data and embedded image data. · github.com, 8 Oct 2026
Project storage: Editable projects use the .sfproj format and autosave in browser localStorage. · github.com, 9 Oct 2026
Purpose: SpriteForge is a browser-based editor for rigged 2D sprite animation. · github.com, 9 Oct 2026
Rigging and animation: Users can import images, build a parent-child bone hierarchy, pose characters, and animate them on a timeline. · github.com, 8 Oct 2026
Runtime integration: Exported bundles are intended for compatible Spine-style runtimes and can also be previewed in the included standalone runtime.html player. · github.com, 8 Oct 2026

Where SpriteForge stands on Freedom251

2D Character Animation Software#28 of 48
2D Game Animation Software#18 of 25