LanguageTool
Multilingual grammar and style checker, one of the rare AI tools that truly masters French
Overview
LanguageTool is an open-source grammar and style checker developed in Germany, covering 30+ languages including a particularly advanced French correction engine (agreement, conjugation, punctuation, repetition, style). The free version corrects basic mistakes; the Premium plan adds 20,000+ extra correction rules, AI-powered sentence rewriting and support for texts up to 150,000 characters. The tool installs as a browser extension, Word/Google Docs/LibreOffice module or desktop app, and covers most daily writing needs for SMEs and freelancers.
Unlike most AI checkers dominated by English, LanguageTool offers a dedicated French grammar checker page and genuine linguistic expertise in that language, making it a credible alternative to Grammarly for French speakers. A REST API is available for developers wanting to embed correction in their own tools, with free quotas then volume pricing. The Teams plan allows sharing a Premium subscription for up to 20 members at tiered pricing.
Our verdict
Recommended as a priority for French-speaking freelancers and SMEs who want reliable French correction without depending on an English-first tool: good value, API available and open-source for technical teams. Not suitable if you're looking for complete content generation: LanguageTool corrects and rewrites but doesn't draft articles or long texts from scratch.