grammai

Free grammar checking. Bring your own Claude Code or Codex for AI rewrites, translation and context checks.

AI writing assistance. Free & open source. grammai helps you catch mistakes, find clearer wording and translate without leaving the text field. English and German spelling and grammar checks run on your device, using engines and dictionaries included in the extension. CHECK YOUR WRITING, RIGHT WHERE YOU WRITE • Automatic English and German detection, with American or British English spelling. • Inline spelling and grammar underlines. Hover to highlight, click to review, then accept or dismiss. • Contextual rules and common word-confusion checks. • Personal dictionary, per-site controls and undo for grammai edits. BRING YOUR OWN AI • Rewrite for clarity, brevity or tone, with a preview before applying. • Save your own named rewrite prompts. • Translate between English and German and replace the selection in one action. Undo restores the original. • Request an AI context check for a broader review. Optional AI actions use your own installed, signed-in Claude Code or Codex CLI and its account limits. The current local AI connection requires macOS, Node.js 22+ and a one-time helper installation. The built-in guide walks you through it. An AI subscription is not included. Ordinary grammar checks need none of this setup. A QUIETER WRITING TOOL The action pill appears only when you select text. Use light or dark mode, keyboard shortcuts and a compact assistant. Supported editors include ordinary text fields, contenteditable fields and tested Draft.js flows such as X-style social editors. PRIVATE BY DEFAULT Ordinary checks stay on your device. There are no analytics trackers or automatic text uploads. Only an AI action you request sends text through your chosen provider's CLI. Provider privacy terms and account settings apply. Send feedback opens an email draft for you to review and send. BUILT WITH THE COMMUNITY The extension is free and open source under GPL v3. Bug reports, grammar fixes, editor improvements and feature pull requests are welcome. Source: https://github.com/zilvestro/grammai Support: https://github.com/zilvestro/grammai/issues Email: grammai@zaapp.io Sponsored by Affonso: https://affonso.io A static sponsor attribution, without tracking. EARLY RELEASE Suggestions can be wrong, especially on short or mixed-language text. Dedicated Google Docs canvas support and full coverage of every rich-text editor are not available yet. AI translation currently supports English and German. Share small, anonymized examples to help us improve. grammai is independent and is not affiliated with Grammarly, LanguageTool, Anthropic or OpenAI.