LanguageTool, Joute's Review

The Essentials in 20 Seconds

Spell and grammar checker for 30+ languages including English
Open source, with self-hosting option (no data sent to third parties)
Browser extension, MS Word integration, Google Docs, LibreOffice
Price: free with limits, Premium at $6/month

Verdict: LanguageTool is the reference for anyone who wants a serious checker. The free plan is generous, and $6/month is very reasonable for the full version. Natural choice if you write in multiple languages.

What is LanguageTool

LanguageTool is an open source grammar and spell-checking tool created by Daniel Naber in 2003 and maintained since by a German team. It detects grammar errors, style mistakes, repetitions, and clunky phrasing in 30+ languages.

The cloud version is accessible via API and browser extension. The self-hosted version lets you run LanguageTool on your own server without sending data anywhere.

Strengths

Excellent multilingual support

LanguageTool was built with multiple languages as first-class citizens. It detects complex agreements, grammatical subtleties, and typically awkward phrasings across languages — something Grammarly, primarily optimized for English, doesn't match.

Open source and self-hostable

Source code is on GitHub. You can run LanguageTool locally without sending your texts to external servers. For confidential documents or companies with data constraints, this is a strong argument.

Wide integrations

Chrome/Firefox extension, Word plugin, Google Docs plugin, CLI, REST API. LanguageTool integrates everywhere you write.

Limits

Less modern interface than Grammarly

LanguageTool's user experience is functional but not as polished as Grammarly. AI rephrasing suggestions are less creative.

AI suggestions are basic

Alternative phrase generation is less impressive than Grammarly Go or AI writing tools. LanguageTool is a checker, not a writer.

Pricing

Free: 20,000 characters/message, basic rules
Premium: $6/month (all rules, style, paraphrase)
Teams: custom pricing

Alternatives

Grammarly for the English-language reference with more AI features
Linguix for a lightweight alternative
ProWritingAid for authors of long-form texts

Verdict

LanguageTool is the default choice for anyone correcting text in multiple languages. The free plan is enough for personal use, and $6/month is practically free for the Pro. If you write seriously, install it now.