Recompresses every PNG
Every texture is re-encoded in the smallest PNG format its pixels allow, with its metadata dropped. In Lossless mode, every pixel stays exact.
Resource Pack Optimizer
Drop in a pack, get a smaller one back: textures recompressed, JSON minified, junk removed. Like PackSquash, with nothing to install.
Drop your resource pack .zip hereor click to choose one. It stays on your computer.
Lossless: every pixel stays exactly as the game sees it.
How it works
What the optimizer does to your pack
The same jobs PackSquash does, in a browser tab. A smaller pack downloads faster for every player who joins your server.
Minifies JSON
Models, blockstates, fonts and sounds.json lose their whitespace and comments. A file that does not parse is left alone and reported to you.
Removes junk
__MACOSX folders, .DS_Store and Thumbs.db go, and if you ask, so do Photoshop, GIMP, Krita and Aseprite files that nothing ever reads.
Fixes the folder
Zipped the folder rather than what is inside it? Minecraft cannot see that pack, so the optimizer moves pack.mcmeta back to the top of the zip.
Step by step
How to make a resource pack smaller
A big pack slows down every player's join. Most of its size is usually textures saved far bigger than they need to be.
- 1
Drop in the zip
Choose your resource pack's .zip at the top of this page. It is read and optimized in your browser, so even a pack of hundreds of megabytes is never uploaded anywhere.
- 2
Pick Lossless or Smaller
Lossless never changes a pixel and suits any pack. Smaller reduces big textures to 256 colours for a far larger saving, and suits high-resolution packs without shaders.
- 3
Download and test
Download the optimized zip, load it in Minecraft or set it as your server's pack, and check it looks the same. The report beneath lists every file that changed and by how much.
Free tools
More for pack makers
Every one free, with no account, and nothing uploaded.
Texture Compressor
Compress PNG textures one at a time or in batches, lossless or like TinyPNG.
Open Resource Pack Merger
Merge packs into one, combining lang, sounds, fonts and custom model data.
Open Resource Pack Checker
Find what is broken: pack.mcmeta, missing textures and models, bad JSON.
Open pack.mcmeta Generator
Write a pack.mcmeta that every version you pick accepts, 1.21.9+ included.
Open Pack Format Versions
Every pack_format number from 1.6.1 to 26.3 and the versions each covers.
Open FAQ
Resource Pack Optimizer FAQ
Is this the same as PackSquash?
It does PackSquash's main jobs: lossless PNG recompression, with OxiPNG (the optimiser PackSquash itself uses) as a second pass, JSON minification, and removing files nothing reads. Unlike PackSquash's defaults, it never deletes OptiFine files or anything else it does not recognise, it reads 1.21.9+ pack.mcmeta files, and it checks every texture pixel for pixel before keeping it.
Can the optimizer break my resource pack?
It is built not to. Files it does not understand, such as OptiFine models and connected textures, shaders and anything a plugin reads, are kept byte for byte. Every texture it rewrites is decoded again and compared with the original pixel for pixel, every JSON file is read back and compared, and anything that differs is kept as it was.
Will the optimizer change how my textures look?
Not in Lossless mode: every pixel is the same as the game reads it. Smaller mode reduces large textures to 256 colours and clears the colour of fully transparent pixels, like TinyPNG, which is usually invisible but not exact. Fonts, shaders and colour maps are always kept exact.
How much smaller will my pack get?
It depends on how the pack was made. Packs exported straight from image editors often lose 20 to 40 percent in Lossless mode; packs already run through an optimizer may not shrink at all, and then you get the original back rather than a bigger file. Smaller mode commonly cuts high-resolution textures by more than half.
Is my pack uploaded?
No. Everything happens in your browser: your files never leave your computer, and there is no account to make.
Does it work with server resource packs, ItemsAdder or Nexo packs?
Yes. The output is an ordinary resource pack zip with the same files at the same paths. Custom model data, item definitions, fonts and overlays are all kept.
How do I reduce the size of a Minecraft resource pack?
Recompress its textures, minify its JSON and remove files the game never reads. This optimizer does all three in one go: drop in the zip and download the smaller one. If you need it smaller still, Smaller mode reduces big textures to 256 colours.
Does a smaller pack make Minecraft run faster?
It downloads and unzips faster, which shortens every player's join on a server. Once loaded, the game holds the same pixels either way, so frame rate does not change.
What is a PackSquash alternative that runs online?
This one. It covers PackSquash's main jobs, lossless PNG recompression, JSON minification and removing unused files, in a browser tab with nothing to install.