Packrat

Packrat is a fast, portable sprite atlas packer for organizing source images into optimized atlas pages.

Built with Zig and Dear ImGui, Packrat can handle thousands of assets while staying simple to use:

• Visual GUI for projects, packing settings, previews, and exports
• CLI for automation, validation, conversion, and watch mode
• One portable executable
• Export support for LibGDX, LÖVE, MonoGame, Raylib, SDL, Phaser, PixiJS, JSON, Pure C, and more
• Generated drop-in code for DIY engines and custom workflows

Pack your sprites once and get clean, runtime-ready output wherever you need it.

Read the Documentation

Insanely Fast

Tested against real-world use cases with 4k individual input assets and a 4096x4096 output image:

1. ~1 second project load times
2. ~1 second repack times
3. ~4 second export time

Insanely Portable

Packrat is just a single executable. Download it and drop it wherever you want. It has a GUI mode that lets you visualize and perfect the settings of your packrat project, and a CLI mode that lets you integrate it into your workflow.

In both GUI and CLI mode, Packrat can watch for changes to a projects inputs, and automatically regenerate the output. 

Insanely Useful

Packrat generates a bunch of common data formats for different frameworks to import directly. And for frameworks and engines that don't inherently support texture atlases, Packrat generate code instead of data, which lets you easily load frames out of the atlas. 

For input, Packrat can take in png, bmp, and tga, as well as aseprite files. For aseprite, it will properly handle multiple frames and tagged animations.