Sprite Sheet Workbench

Turn loose animation frames into a sprite sheet with consistent spacing. Sprite Sheet Workbench trims transparent borders, aligns frames, and lets you check the animation before exporting a PNG atlas and engine files.

The complete prototype is free, with optional donations. There is no paid feature unlock. The app interface is in Japanese; the control guide below will help you get started.

From frames to a playable animation

1. Click サンプルを試す to load six built-in sample frames, or 画像を追加 to add your own PNG, WebP, or JPEG images.
2. Use the arrows to reorder frames. Choose bottom alignment for a shared foot position, center alignment, or the original canvas coordinates. Adjust columns, padding, and playback speed.
3. Click まとめて書き出す to download the export ZIP. Read its IMPORT.txt for engine setup.

Images stay in your browser. Settings can be saved in browser storage; images are cleared when you reload, so export your work first. No account is needed.

What the export includes

• A PNG atlas and ordered frame data in a custom JSON format.
• A Godot 4 SpriteFrames resource. Keep frames.tres beside atlas.png and assign it to an AnimatedSprite2D. Resource loading was checked in Godot 4.7.2.
• Unity coordinate data and an experimental C# importer for new imports. Intended for Unity 2022.3 LTS / Unity 6 with the 2D Sprite package. It has been tested against API stubs, not inside Unity. It does not update existing sprite imports or create Animation Clips.

Requirements and limits

Use desktop Chrome; Windows Chrome is the tested browser. Launch this itch.io browser build directly: you do not need Node.js. Other browsers and mobile devices have not been verified.

Up to 128 still frames, 4096 pixels per input edge, 16,777,216 input pixels in total, 64 MiB of input files, and 4096 pixels per output edge. These limits keep browser memory use bounded. Frames use equal-sized cells, with no rotation or scaling. Animated WebP is unsupported, and JPEG backgrounds stay opaque. This tool assembles separate images; it does not slice an existing sheet.

The app and its procedural samples are MIT licensed. Use images you have permission to process.