This article is about Minecraft.jar. For the front-end Minecraft client, see Minecraft launcher.

minecraft.jar is the main code source for Minecraft. It is located in the ../minecraft/versions/(current version) directory, or ../minecraft/versions/(current version) on OS X. When using the latest version of the minecraft launcher, it is named <gameversion>.jar

It can be opened using a file archiving program or a Java decompiler.

Jar versions

The minecraft.jar file is found in its version folder. It is accompanied by a .json file that lists the version's attributes. Normal and snapshot versions are available to choose from via the minecraft launcher. It's even possible to download alpha versions, and create one's own version file to install mods on. Note that creating a new version is the only way to install mods; the launcher keeps normal versions synced.

Files in minecraft.jar

In minecraft.jar many files can be found, they can be categorized like this:

  • Texture files: Textures used by Minecraft (all in .png format).
  • Class files: Compiled Java code that Minecraft uses for program logic. These files (classes) are named like "acq" or "qn" because they have been run through an obfuscation tool to hide the names of methods, variables, and classes. However, they can still be disassembled to understand their functionality.
  • Language files: Language files are used to change the messages in the game (achievements, tooltips, menu). It does not affect in-game chat.
  • Text files: Files that contain easy to edit text, such as splashes and texture pack descriptions, another text file is achievements/map.txt that contain code for the creation of the achievements menu background.
  • The META-INF directory: Contains information about the game files.