LanguageTool is a style and grammar proofreading software for English, French, German, Polish, Dutch, Romanian, and a lot of other languages. You can think of LanguageTool as a software to detect errors that a simple spell checker cannot detect, e.g. mixing up there/their, no/now etc. It can also detect some grammar mistakes. It does not include spell checking.

LanguageTool will find errors for which a rule is defined in its language-specific configuration files. Rules for detecting more complicated errors can be written in Java.

Try it online

Download

Download LanguageTool 1.6 (29 MB)

• Requires Java 6.0 or later. You need to restart OpenOffice.org/LibreOffice after installation of this extension.
• If you're upgrading from LanguageTool 0.9.5, you must de-install it before upgrading to a later version (check this page if you forgot to do so).
• Please report bugs to the Sourceforge bug tracker or post to our forum.

Try LanguageTool 1.6 without installation, using Java WebStart. Requires Java 1.6_04 or later.
Start LanguageTool (29 MB)

Untested daily snapshots of the current development version are available at the snapshot directory (CHANGES.txt).

News

2011-12-31: Released LanguageTool 1.6. Changes include:

• Rule updates for several languages (Chinese, French, Breton, and others)
• Renamed the Java packages from de.danielnaber.languagetool.* to org.languagetool.*
• For a more detailed list of changes, see the Changelog

2011-11-18: We now offer Wikicheck, a new service to check Wikipedia pages with LanguageTool

2011-09-25: Released LanguageTool 1.5. Changes include:

• Support for new languages: Chinese, Asturian, Breton, and Tagalog
• Automatic language detection (not relevant for OpenOffice.org/LibreOffice)
• Many rule updates for several languages
• For a more detailed list of changes, see the Changelog

2011-08-28: Our Google Summer of Code students have successfully finished their projects and the results will be part of LanguageTool 1.5, to be released in about one month.

Installation and Usage

• In OpenOffice.org/LibreOffice: Double click LanguageTool-1.6.oxt to install it. If that doesn't work, call Tools -> Extension Manager -> Add... to install it. Close OpenOffice.org and re-start it. Type some text with an error (e.g. "This is an test." – make sure the text language is set to English) and you should see a blue underline.
• Also see Usage for using LanguageTool outside of OpenOffice.org.

Need Help?

Please see the list of common problems.

License & Source Code

LanguageTool is freely available under the LGPL. The source is available at Sourceforge via SVN. The contents of this homepage is available under CC BY-SA 3.0.