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An easy and lightweight launcher for Minecraft which takes some of the hassle away.

Due to the way Minecraft is launched beginning with the 1.6 snapshots and the 1.6 release it is not possible to launch these versions with EasyMineLauncher.

What it does:

  • Removes the need to login if you just want to play offline or on a private server
  • There's no check for an update, you're directly catapulted to the main menu or connected to a server
  • Additional parameters (f.e. start as maximized window or loading of certain versions from different directories)

What it does not:

  • Remove the need to authenticate at servers if they demand it
  • Loading and applying updates
  • Lets you play Minecraft for free, you'll still need to get an account and download the binaries

How does it work?

Basically this is just mimicking the behavior of the official launcher, except that it removes the online authentication and the update process. I figured most of that out with Trial & Error, that's why it's looking a little bit crude and has debugging output all over the place.


This launcher is compatible with the following versions:

  • Indev
  • Infdev
  • Alpha
  • Beta
  • 1.0 - 1.5

This launcher does not work with the 1.6 snapshots and release or any later version.

Where to get it?

Ready-to-use jars are available from the Download-Section.

What can I do with it?

Awesome stuff?

Here's the output from --help:

Usage: EasyMineLauncher.jar [OPTION]
Launch Minecraft directly.

--help                   Prints this help.
--version                Prints the version.

--jar-dir=DIRECTORY      Set the directory for the jar files.
--jar=MINECRAFT.JAR      Set the path to the minecraft.jar.
                         Either specify jar-dir or this.
--lwjgl-dir=DIRECTORY    Set the directory for the jar files
                         of lwjgl (lwjgl.jar, lwjgl_util.jar, and jinput.jar)
--password=PASSWORD      Set the password.
--mppass=MPPASS          Same as --password=PASSWORD (backwards compatibility)
--native-dir=DIRECTORY   Set the directory for the native files of lwjgl.
--additional-jar=JAR     Load the specified jars.
                         This might be needed by some mods.
                         Specify multiple times or list separated with ','.
--parent-dir=DIRECTORY   Set the parent directory. This effectively changes
                         the location of the .minecraft folder.
--applet=APPLET          The (full) name of the applet to load. Normally this
                         points to the Minecraft-Applet.
--blend-with=JAR         Blend the (found) minecraft.jar with JAR.
                         That means that the content of JAR is copied into
                         a temporary jar and then is supplemented with the
                         missing files from minecraft.jar.
                         Please be aware that this means that two archives are
                         merged together at every start, that takes on my SSD
                         a whooping 1.2 seconds.
--blend-jar-name=NAME    The NAME of the blended jar, defaults to
--blend-keep-manifest    Copy the manifest from the given JAR to blend...that
                         might not work.
--port=PORT              Set the port of the server, if not set it will revert
                         to 25565.
--texturepack=FILE       Set the texturepack to use, this takes only
                         the filename (including extension).
                         Use 'Default' for default.
--server=SERVER          Set the address of the server which directly
                         to connect to.
--authenticate           Use the given username and password to authenticate
                         at the Mojang server. This will override the given
                         session id (if given) and the username with that
                         returned from Mojang (case corrected).
--authentication-failure=Set the behavior if the authentication fails,
                         following values are possible:
  SILENT_CONTINUE        Just continue, there will only be a notification
                         on the error output.
  ALERT_CONTINUE         Display a dialog with the reason why it failed,
                         but still continue on.
  SILENT_BREAK           Stop execution and exit, there will only be
                         a notification on the error output.
  ALERT_BREAK            Stop execution and exit, and also display a dialog
                         with the reason why authentication failed.
                         This is the default behavior.
--keep-alive-tick=TICK   Set the interval (in seconds) in which the
                         authentication at the Mojang server is renewed.
                         Default is 300 seconds.
--session-id=SESSIONID   Set the session id.
--launcher-version=VER   Report this launcher version when authenticating.
                         Default is "381".
--auth-address=ADDRESS   Authenticate at this address instead of
                         the Mojang server.
--options-file=FILE      Copy the options.txt from this location.
                         Please be aware that this overwrites the options.txt
                         in the Minecraft directory. This will also be done
                         before --texturepack and --set-option.
--set-option=NAME:VALUE  Set this option in the options.txt file.
--username=USERNAME      Set the username to user.
--use-lastlogin          Read username and password from the lastlogin file
                         within the parentdir. Overrides provided username and
--save-lastlogin         Writes back the username and password into
                         the lastlogin file, but only after successfull
                         authentication (therefor --authenticate must be
                         provided, too).
--keep-username          Do not override the username with that returned from
                         Mojang. Only applies when --authenticate is provided.
--demo                   Trigger Demo-Mode. This might break other stuff.

--title=TITLE            Replace the window title.
--height=HEIGHT          The width of the window.
--width=WIDTH            The height of the window.
--x=X                    The x-location of the window.
--y=Y                    The y-location of the window.
--maximized              Maximize the window.
--no-frame               Remove the border of the window.
--always-on-top          Make the window stay above all others.
--fullscreen             Makes the window the same size as the whole desktop.
                         This is basically shorthand for
                         This might yield odd results in multi-monitor
--opacity=OPACITY        Sets the opacity of the window, were 1 is fully
                         visible, 0 is invisble and 0.5 is half visible.
                         This might or might not work depending on your WM and
                         or compositor. This also forces --no-frame.
--dump                   Chickens out before doing anything and prints all
                         of the configuration values.
--no-exit                Does not exit on failure (if Minecraft could not be
                         loaded), only returns.

You can also keep different versions around and launch them with ease, f.e. with such a directory/file-layout:

 +- Beta 1.6.6.jar (renamed minecraft.jar)
 +- Beta 1.7.3.jar
 +- Beta 1.8.2.jar
 +- lwjgl
     +- lwjgl jars go here
 +- natives
     +- lwjgl natives go here

With the following command you can launch the versions:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --jar=./bin/Beta \1.6.6.jar --lwjgl-dir=./bin/lwjgl/ --native-dir=./bin/natives/ --username=Terminator

Notes on the parameters


This will allow you to load other jars into memory. Please be aware that this does nothing but load the jars so that they're available via reflection. There are some mods which need external jars or the official can specify them with this.

You can specify this either multiple times:

  --additional-jar=./first.jar --additional-jar=./second.jar --additional-jar=./third.jar

Or you can specify a list, whatever suits your needs:


There's also the possibility that this might not work, drop an Issue with the mod and I'll have a look.


This will allow you to change the location of the minecraft directory which is normally located in ~/. Please be aware that this will only change the location of the .minecraft directory, f.e. /mnt/data/Minecraft/Data/ becomes /mnt/data/Minecraft/Data/.minecraft/.


Please be aware that this option does merge two archives together. So depending in your machine, this may take between 1 and 10 seconds every start. how do I compile this?

The easy way

Download the ready-to-use jar from the Download-Section.

The normal way

Run ant.

The hard way

  1. Create a manifest file MANIFEST.MF in the base directory with the following content:

    Manifest-Version: 1.0
    Main-Class: org.bonsaimind.easyminelauncher.Main
  2. Execute the following commands:

    $ mkdir build dist
    $ javac -d build src/org/bonsaimind/easyminelauncher/*
    $ jar -cvfm dist/EasyMineLauncher.jar MANIFEST.MF -C build build/org/bonsaimind/easyminelauncher/*
  3. Find the ready-to-use jar in dist.


Launch whatever is installed (same as hitting "Offline Mode" in the official launcher):

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar

Launch the current version of Minecraft with a certain username:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --username=MyAwesomeName

Launch the current version of Minecraft with an updated lwjgl version which resides in a different directory:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --lwjgl-dir=/home/user/updatedLWJGL/ --native-dir=/home/user/updatedLWJGL/native/ --username=MyNotSoAwesomeName --maximized

Launch the current version of Minecraft and directly connect to a server:

java -Xmx1536M -Xms1536M -jar EasyMineLauncher.jar --username=MyAwesomeName

Launch specific jar, with different lwjgl directory, connect to a server on a different port, maximize the window and rename it:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --jar=./bin/Beta\ 1.7.3.jar/ --lwjgl-dir=./bin/lwjgl/ --native-dir=./bin/natives/ --username=Octiface --port=666 --maximized --title=UberGame

A simple portable launcher:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --jar-dir=./bin/ --parent-dir=./

Authenticate at Mojang:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --username=YourOfficialName --password=shutup --authenticate

Or maybe like this:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --use-lastlogin --authenticate

Some more authentication options:

java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar --username=YourUsername --password=shooooootu --authenticate --keep-alive=240 --authentication-failure=ALERT_CONTINUE

Not so fast...

...okay, step by step.

How do make your Minecraft portable, if you already have a .minecraft directory, skip to step 4:

  1. Start the official launcher, download the binaries

  2. Launch Minecraft one time to create the data directory and necessary files

  3. Exit Minecraft

  4. Copy the ~/.minecraft directory to /media/yourUsbStick/

  5. Rename it to something more meaningful

  6. Create a sript with the following contents:

    #, /media/yourUsbStick/MinecraftPortable/
    java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar \
      --jar-dir=./bin/ \
      --parent-dir=./ \
  7. Make the script executable, done.

Okay, now to something more sophisticated, let's extract and split the .minecraft directory so that we can have multiple versions with ease (assuming you already have different versions and a .minecraft dir):

  1. Create a directory as target, e.g. ~/Minecraft/

  2. Create the following sub-directories: bin, data, lwjgl and natives

  3. Copy ~/.minecraft/bin/minecraft.jar to ~/Minecraft/bin/VERSION.jar

  4. Copy ~/.minecraft/bin/*.jar to ~/Minecraft/lwjgl/*.jar

  5. Copy ~/.minecraft/bin/natives/*.so to ~/Minecraft/natives/*.so

  6. Copy everything from ~/.minecraft/ to ~/Minecraft/.minecraft/ except the bin directory

  7. Copy the EasyMineLauncher.jar into ~/Minecraft/

  8. Create the script and make it executable:

    #, ~/Minecraft/
    java -Xmx1024M -Xms1024M -jar EasyMineLauncher.jar \
      --jar=./bin/$1.jar \
      --lwjgl-dir=./lwjgl/ \
      --native-dir=./natives/ \
      --parent-dir=./data/ \
      --username=YourOfflineUsername \
      --title=Minecraft\ $1
  9. Create a version specific script and make it executable:

    #, ~/Minecraft/
    ./ VERSION
  10. Repeat steps 3 and 9 to add further versions.

Problems? Let's see...


If you're using a mod and you're getting a ClassNotFoundException: net.minecraft.Launcher error, you need to specify the original Minecraft-Launcher with the --additional-jar option.

Dude, my achievements are gone!

Oh yeah, should have told you before, somehow version hopping seems to mess up the achievements, so you might lose all of them.


A free and simple launcher for Minecraft.




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