LanguageTool
Open SourceOpen-source grammar and style checker supporting 30+ languages.
About LanguageTool
Open-source grammar and style checker supporting 30+ languages.
Key Features
- ✓30+ Languages: Full grammar and style checking in English, German, French, Spanish, Portuguese, Polish, Dutch, Russian, Chinese, Arabic, and more.
- ✓Open Source: Self-host on your own server for complete data privacy and control.
- ✓Privacy-First: No text stored on servers (cloud version), no tracking, no ads in Premium.
- ✓Style Checking: Detects overused words, redundant phrases, and suggests improvements beyond basic grammar.
- ✓Picky Mode (Premium): Catches additional style issues like filler words, unnecessary nominalizations, and repeated words.
- ✓Browser Extension: Works in Chrome, Firefox, Edge, Safari, Google Docs, Gmail, and more.
- ✓API Access: REST API for integrating grammar checking into your own applications — free tier available.
Pricing
| Plan | Price | Key Features |
|---|---|---|
| Free | See official pricing | 20, 000 characters/check, all languages, browser extensions, basic suggestions |
| Premium | See official pricing | Unlimited text, Picky Mode, advanced style checks, no ads, personal dictionary |
| Teams | See official pricing | Premium features + custom rules, admin dashboard, centralized billing |
| Self-Hosted | See official pricing | Full open-source version, unlimited, run on your own infrastructure |
Some pricing plans have not been verified against official sources recently. Confirm on the official pricing page before purchasing.
Pros & Cons
✅ Pros
- ✅ Best multilingual grammar checker — 30+ languages with deep analysis
- ✅ Open source and self-hostable — full data privacy
- ✅ Very affordable Premium at $5/month
- ✅ No tracking or data selling — privacy-first philosophy
- ✅ Free API for developers and integration
- ✅ Works in Google Docs, email, and most web apps
⚠️ Cons
- ⚠️ English checking not as polished as Grammarly
- ⚠️ Free tier limited to 20,000 characters per check
- ⚠️ No AI-powered rewriting or sentence generation
- ⚠️ Self-hosting requires technical setup and maintenance
- ⚠️ Fewer integrations than commercial competitors
Use Cases
Daily Workflows
Integrate LanguageTool into your daily routine for faster, more accurate results.
Goal Achievement
Use AI insights to stay on track with your objectives. Progress tracking and recommendations included.
Idea Generation
Brainstorm new concepts with AI. Generates creative solutions and alternative approaches.
Alternatives
Frequently Asked Questions
Is LanguageTool free?
Yes, LanguageTool is free with a 20,000 character limit per check, covering all 30+ languages. Premium at $5/month removes the limit and adds Picky Mode with advanced style suggestions. You can also self-host the open-source version for free with no limits.
Is LanguageTool better than Grammarly?
Grammarly has more polished English checking and AI-powered rewriting. LanguageTool wins on multilingual support (30+ languages vs Grammarly's English focus), privacy (open-source, self-hostable), and price ($5/mo vs $12/mo). Choose Grammarly for English-only writing; LanguageTool for multilingual or privacy-conscious users.
Can I self-host LanguageTool?
Yes, LanguageTool is open-source (LGPL license) and can be self-hosted on your own server. This gives you unlimited checking, full data privacy, and no external dependencies. The self-hosted version uses the same rules engine as the cloud version, though the Premium-only "Picky Mode" AI features require a subscription.
What languages does LanguageTool support?
LanguageTool supports 30+ languages including English, German, French, Spanish, Portuguese, Polish, Dutch, Russian, Chinese, Japanese, Arabic, Persian, Italian, Catalan, Danish, Slovak, Slovenian, Swedish, Tamil, Ukrainian, and more. Each language has dedicated grammar rules developed by language experts.