AI Tools

3 Free & Open Source Alternatives to Grammarly (2026)

Find the best free and open-source alternatives to Grammarly for grammar checking, style improvement, and AI writing help in 2026.

Quick Comparison

Tool Pricing Description Top Pros Top Cons Link
LanguageTool
Free & Open Source

Free tier with core grammar and spell checking; Premium at ~$5/month adds advanced style, clarity, and plagiarism detection.

An open-source grammar, style, and spell checker supporting over 30 languages, available as a browser extension, desktop app, and self-hosted service.
  • Open source under LGPL — self-host for unlimited checks with complete privacy
  • Supports over 30 languages, far exceeding Grammarly's language coverage
  • AI-powered style and clarity suggestions require the paid Premium plan
  • Writing tone and engagement scoring is not as polished as Grammarly Premium
H Hemingway Editor
Free

Free to use in the browser at hemingwayapp.com with full functionality; one-time $19.99 purchase for the desktop app.

A writing tool that highlights complex sentences, passive voice, and readability issues to help you write clearly and concisely.
  • Free to use in the browser with no account or sign-up required
  • Focuses on clarity and readability rather than rigid grammar rules
  • Not open source; works only within its own editor with no integrations or API
  • Does not check grammar or spelling — purely style and readability feedback
V Vale
Free & Open Source An open-source command-line prose linter that enforces custom style guides for Markdown, AsciiDoc, HTML, and other markup formats.
  • Fully open source under MIT — extend, fork, or self-host with no restrictions
  • Highly configurable via custom rules; supports Google, Microsoft, and Write Good style guides
  • Command-line only — no GUI or browser extension; not suitable for non-technical users
  • Requires setup and configuration before use; not a drop-in replacement for Grammarly

Detailed Reviews

LanguageTool

Free & Open Source

Free tier with core grammar and spell checking; Premium at ~$5/month adds advanced style, clarity, and plagiarism detection.

An open-source grammar, style, and spell checker supporting over 30 languages, available as a browser extension, desktop app, and self-hosted service.

Pros

  • Open source under LGPL — self-host for unlimited checks with complete privacy
  • Supports over 30 languages, far exceeding Grammarly's language coverage

Cons

  • AI-powered style and clarity suggestions require the paid Premium plan
  • Writing tone and engagement scoring is not as polished as Grammarly Premium
H

Hemingway Editor

Free

Free to use in the browser at hemingwayapp.com with full functionality; one-time $19.99 purchase for the desktop app.

A writing tool that highlights complex sentences, passive voice, and readability issues to help you write clearly and concisely.

Pros

  • Free to use in the browser with no account or sign-up required
  • Focuses on clarity and readability rather than rigid grammar rules

Cons

  • Not open source; works only within its own editor with no integrations or API
  • Does not check grammar or spelling — purely style and readability feedback
V

Vale

Free & Open Source

An open-source command-line prose linter that enforces custom style guides for Markdown, AsciiDoc, HTML, and other markup formats.

Pros

  • Fully open source under MIT — extend, fork, or self-host with no restrictions
  • Highly configurable via custom rules; supports Google, Microsoft, and Write Good style guides

Cons

  • Command-line only — no GUI or browser extension; not suitable for non-technical users
  • Requires setup and configuration before use; not a drop-in replacement for Grammarly

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