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LanguageTool is an Open Source proofreading software for English, French, German, Polish, Russian, and more than 20 other languages. It finds many errors that a simple spell checker cannot detect.

LanguageTool is freely available under the LGPL 2.1 or later.

For more information, please see our homepage at, this README, and CHANGES.


The development overview describes how you can contribute error detection rules.

See 'easy fix' issues for issues to get started.

For more technical details, see our wiki.

Scripted installation and building

To install or build using a script, simply type:

curl -L | sudo bash <options>
sudo bash <options>
Usage: <option> <package>
   -h --help                   Show help
   -b --build                  Builds packages from the bleeding edge development copy of LanguageTool
   -c --command <command>      Specifies post-installation command to run (default gui when screen is detected)
   -q --quiet                  Shut up LanguageTool installer! Only tell me important stuff!
   -t --text <file>            Specifies what text to be spellchecked by LanguageTool command line (default spellcheck.txt)
   -d --depth <value>          Specifies the depth to clone when building LanguageTool yourself (default 1).
   -p --package <package>      Specifies package to install when building (default all)
   -o --override <OS>          Override automatic OS detection with <OS>
   -a --accept                 Accept the oracle license at Only run this if you have seen the license and agree to its terms!
   -r --remove <all/partial>   Removes LanguageTool install. <all> uninstalls the dependencies that were auto-installed. (default partial)

Packages(only if -b is specified):
   standalone                  Installs standalone package
   wikipedia                   Installs Wikipedia package
   office-extension            Installs the LibreOffice/OpenOffice extension package

   GUI                         Runs GUI version of LanguageTool
   commandline                 Runs command line version of LanguageTool
   server                      Runs server version of LanguageTool

Alternate way to build from source

Before start: you will need to clone from GitHub and install Java 8 and Apache Maven.

Warning: a complete clone requires downloading more than 360 MB and needs more than 500 MB on disk. This can be reduced if you only need the last few revisions of the master branch by creating a shallow clone:

git clone --depth 5

A shallow clone downloads less than 60 MB and needs less than 200 MB on disk.

In the root project folder, run:

mvn clean test

(sometimes you can skip Maven step for repeated builds)

./ languagetool-standalone package -DskipTests

Test the result in languagetool-standalone/target/.

./ languagetool-wikipedia package -DskipTests

Test the result in languagetool-wikipedia/target.

./ languagetool-office-extension package -DskipTests

Test the result in languagetool-office-extension/target, rename the *.zip to *.oxt to install it in LibreOffice/OpenOffice.

Now you can use the bleeding edge development copy of LanguageTool *.jar files, be aware that it might contain regressions.


Unless otherwise noted, this software is distributed under the LGPL, see file COPYING.txt.