LanguageTool Self-Hosted Server Setup (Use the Extension Free)

How to fix it

// try these in order, the most common fix is first

1. FIX 1Install Java and download the server

   Copy steps
   1. 01Install Java 8 or later
   2. 02Download LanguageTool-latest-snapshot.zip from the LanguageTool snapshots page and unzip it
   3. 03macOS alternative: brew install languagetool (community-maintained)
   Did this fix it? Yes No

2. FIX 2Start the server

   Copy steps
   1. 01Create an empty server.properties file in the unzipped folder
   2. 02Run: java -cp languagetool-server.jar org.languagetool.server.HTTPServer --config server.properties --port 8081 --allow-origin
   3. 03On macOS with Homebrew: brew services start languagetool to keep it running
   Did this fix it? Yes No

3. FIX 3Test it

   Copy steps
   1. 01Run: curl -d "language=en-US" -d "text=a simple test" http://localhost:8081/v2/check
   2. 02You should get a JSON response
   Did this fix it? Yes No

4. FIX 4Point the extension at your server

   Copy steps
   1. 01Open the extension options (cog icon)
   2. 02Go to Experimental settings
   3. 03Select 'Local server'
   4. 04Safari needs HTTPS: use a reverse proxy and 'Other server' set to https://localhost:8082/v2
   Did this fix it? Yes No

Symptoms

You want the browser extension without paying, or you want text to stay on your own machine.

Why it happens

• C-01The hosted extension is Premium-only
• C-02Privacy requirements that rule out sending text to a cloud service

// this guide also covers

• languagetool self hosted
• languagetool local server
• languagetool free extension workaround
• languagetool docker

The same problem in other apps

All integrations, automations & extensions guides →

• Grammarly Not Working in Google Docs (Grammarly)
• QuillBot Chrome Extension Not Working (QuillBot)
• ProWritingAid Not Working in Google Docs (ProWritingAid)

Other LanguageTool errors

• LanguageTool Extension Stopped Working (Upgrade Required)
• LanguageTool Not Working in Google Docs
• LanguageTool Not Working in Word
• LanguageTool Detects the Wrong Language
• LanguageTool Slow and Using High Memory in Firefox
• LanguageTool Not Working in Overleaf
• LanguageTool Not Working in Chrome
• LanguageTool Text Too Long (Character Limit)