Open Source Grammar Checkers

An AI-powered proofreading tool supports over 20 languages, offering free and premium versions with extensive grammar checks across multiple apps.

Grammalecte is a French grammar checker.

Eloquent is a proofreading software for English, Spanish, French, German, Portuguese, Polish, Dutch, and more than 20 other languages. It finds many errors that a simple spell checker cannot detect.

CapyBro is a Windows tray utility that brings AI to any text on your PC via a global hotkey. Select text in any application (Word, Telegram, Outlook, browser, code editor) and press Ctrl+Shift+E — AI rewrites it in place.

Advanced your language skills with AI.

Highlights potential pitfalls in your writing to encourage good habits.

We use artificial intelligence and natural language processing technology to find your writing errors and offer smart suggestions.

Grammark helps improve writing style & grammar and teaches students to self-edit. Basically, it finds things that grammarians consider bad, highlights them, and suggests improvements.

Naive linter for English prose for developers who can't write good and wanna learn to do other stuff good too.

Command-line grammar checker.

A grammar highlighter for Microsoft Word to make your writing clear and persuasive.

AI-powered grammar correction tool using fine-tuned language models to fix grammatical errors in text.

Scramble is an open-source Chrome extension that leverages AI to enhance your writing directly in your browser. It's designed to be a more customizable and privacy-respecting alternative to Grammarly.