Can I open-source LanguageTool?
YES · mature open-source replacementYes. Ollama (178k stars), Lobe Chat (65k stars), LibreChat (28k stars) are mature open-source replacements for LanguageTool — self-host in one command and stop paying $5.47/mo.
They pay for hosted convenience, premium rules, and cross-device setup.
xpremium rule set
xhosted server convenience
xbrowser extension premium flows
xteam/admin options
xsupport
These projects already replace it, free.
HHarperA fast English grammar checker that stays on your device and mostly keeps its opinions to itself.open source↗WWriting ToolsSelect text anywhere, hit a hotkey, and fix, rewrite, summarize, or obey a custom instruction without opening another tab.open source↗WWritingToolA LibreOffice extension with long-document checks, style statistics, profiles, and local AI; installing Java is the cover charge.open source↗all 7 open-source alternatives to LanguageTool →· no votes, no pay-to-list · just what's real
LanguageTool pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| basic | $0 | $0 | 2,000 characters/text on the live comparison page; 3 AI rephrases/day. |
| premium | $24.90 | $5.83 | 150,000 characters/text; unlimited AI paraphrasing. |
| team | — | $5.47/user | Up to 20 users; Premium feature set. |
free tier2,000 characters/text on the live comparison page; 3 AI rephrases/day
billingmonthly + quarterly + annual + 2-year for individual Premium; Team is annual-only
hidden costsTeam pricing is published in EUR; the USD value is an exchange-rate conversion and card/issuer fees or tax can change the final charge.
verified 2026-08-12 · source ↗
Can I open-source LanguageTool?
Yes. Harper replaces LanguageTool today — self-host it on your own server or machine with no subscription. The full list of open-source alternatives is on this page.
How much does LanguageTool cost?
LanguageTool costs about $5.47/month (Team, checked 2026-08-12), which is $65.64 per year. That's what you save by replacing it with open source.
What do I lose by replacing LanguageTool?
Honestly: premium rule set; hosted server convenience; browser extension premium flows; team/admin options; support. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to LanguageTool?
Yes: Harper (A fast English grammar checker that stays on your device and mostly keeps its opinions to itself.) Writing Tools (Select text anywhere, hit a hotkey, and fix, rewrite, summarize, or obey a custom instruction without opening another tab.) WritingTool (A LibreOffice extension with long-document checks, style statistics, profiles, and local AI; installing Java is the cover charge.) All 7 curated open-source alternatives are at caniopensourceit.online/languagetool/alternatives.