MC-Repack

Why?

MC-Repack was created with a simple thought in mind: How many Minecraft mods and resource packs come with unoptimized files? And I don't mean just pretty-printed JSON files. You will be surprised that in some cases a PNG file's metadata added by Photoshop is much larger than its content.

One other important thing is that MC-Repack determines if a file really needs to be compressed.Most PNG files and smaller JSON files will usually be stored uncompressed. This kind of operation saves bytes if a "compressed" form is larger than original. Also, uncompressed data can be loaded faster.

This is a great tool that can be helpful for:

• Mod developers and resource pack makers – they can provide mods with smaller file sizes, optimized PNGs and correctly formatted JSONs
• Players and server owners – optimized and repacked files can speed up Minecraft load time while using less memory.

MC-Repack shows all errors happened during repacking. Most of them are errors that can be simply ignored (like "trailing comma at line X column Y").

Features

• Minifying JSON files
• Optimizing PNG files
• Optimizing TOML files
• Removing unwanted files – some project files (from Blender, Photoshop, etc.) are mistakenly packed in mods. This operation will detect and remove (ignore while repacking) these files.
• Stripping unneeded Unicode BOM (sometimes found in many files)
• Removing comment lines in many file types: cfg, obj, mtl, zs, vsh, fsh
• Recompressing files more efficiently

Original vs repacked

MC-Repack can save about 10% of file size for larger mods (see data below). It may be difficult to understand, but JAR files are already compressed. The difference of uncompressed files is usually much larger.

• MineColonies

  Tested file: minecolonies-1.19.2-1.0.1247-BETA.jar

  74,630.5 kB
  65,209.6 kB
  Saved: 9,421 kB

• Ice and Fire

  Tested file: iceandfire-2.1.12-1.18.2-beta2.jar

  21,017.8 kB
  15,959 kB
  Saved: 5,058.8 kB

• Blue Skies

  Tested file: blue_skies-1.19.4-1.3.24.jar

  81,271.3 kB
  77,476.6 kB
  Saved: 3,794.7 kB

• Blood Magic

  Tested file: BloodMagic-1.18.2-3.2.6-41.jar

  14,021.5 kB
  12,140.6 kB
  Saved: 1,880.9 kB

• Supplementaries

  Tested file: supplementaries-1.19.2-2.3.7.jar

  14,233.6 kB
  12,815.9 kB
  Saved: 1,417.7 kB

Check all tested mods HERE!

Usage

After installation, the tool can be run by just double-clicking its file. It can also be used by typing the mc-repack command in a terminal/shell.

When a file path is provided, then MC-Repack will repack the file contents into a file ending with _repack.jar. If a path is a directory, then all files inside (non-recursive) will be repacked.

More options are provided by typing mc-repack --help in a shell/terminal.