// troubleshooting guide · languagetool

LanguageTool Extension Stopped Working (Upgrade Required)

Q: How do I fix "LanguageTool Extension Stopped Working (Upgrade Required)"?

1. Check that you are logged in to Premium: Click the LanguageTool icon in the browser toolbar Open the settings (cog icon) Log in with the account that holds your Premium subscription Reload the page you are writing on 2. Use the free web editor instead: Go to languagetool.org Paste your text into the editor (up to 2,000 characters per check on the free plan) Split longer text into chunks 3. Connect the extension to a self-hosted server (free): Run the open-source LanguageTool server on your computer (see our self-hosted server guide) Open the extension options (cog icon) > Experimental settings Select 'Local server' Reload the page; synonyms will not be available 4. Switch to a free extension: LanguageTool itself points free users to QuillBot's free grammar extension (Chrome, Edge, Safari) Firefox users often switch to Harper, a free open-source checker that runs locally

Status: Ongoing
platforms:: Chrome, Firefox, Edge, Safari, Opera
updated:: November 15, 2026
reports:: 5
Method: how we research

RUNBOOK · languagetool/extension-stopped-working4 FIXES

// quick answer

If the extension stopped underlining errors and asks you to upgrade, your 14-day Premium trial has ended: the extension is now Premium-only. Subscribe, connect it to a free self-hosted server, or use the free website editor.

Most likely fix: Check that you are logged in to Premium

How to fix it

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

FIX 1Check that you are logged in to Premium
1. 01Click the LanguageTool icon in the browser toolbar
2. 02Open the settings (cog icon)
3. 03Log in with the account that holds your Premium subscription
4. 04Reload the page you are writing on
Did this fix it?
FIX 2Use the free web editor instead
1. 01Go to languagetool.org
2. 02Paste your text into the editor (up to 2,000 characters per check on the free plan)
3. 03Split longer text into chunks
Did this fix it?
FIX 3Connect the extension to a self-hosted server (free)
1. 01Run the open-source LanguageTool server on your computer (see our self-hosted server guide)
2. 02Open the extension options (cog icon) > Experimental settings
3. 03Select 'Local server'
4. 04Reload the page; synonyms will not be available
Did this fix it?
FIX 4Switch to a free extension
1. 01LanguageTool itself points free users to QuillBot's free grammar extension (Chrome, Edge, Safari)
2. 02Firefox users often switch to Harper, a free open-source checker that runs locally
Did this fix it?

Symptoms

No underlines in Gmail, Docs or other text fields, an 'Upgrade required' message from the extension, paraphrasing and synonyms no longer work, the extension icon shows a lock or upgrade prompt.

Why it happens

C-01LanguageTool made the browser extension Premium-only; the free trial ended
C-02You are logged out of your Premium account in the extension
C-03The site is disabled in the extension settings
C-04A browser bug or update disabled the extension

// this guide also covers

languagetool extension not working
languagetool upgrade required
languagetool no longer free
languagetool extension premium only

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