Best Free Grammar Checkers 2026: 7 Options Compared

Free grammar checkers fall into three groups: cloud tools with a free tier, a tool with an open-source core, and a local checker. Grammarly's free plan covers spelling, grammar, tone suggestions and 100 AI prompts. LanguageTool checks 2,000 characters per text field on its free plan and its LGPL core can be run on your own server, with support for 25+ languages. ProWritingAid's free plan handles up to 500 words at a time, Sapling checks up to 2,000 characters, Wordtune offers unlimited grammar checks with 10 rewrites a day, and QuillBot is free, with limits listed on its pricing page. Harper is an Apache-2.0 checker that runs locally, supports English only, and plugs into editors such as VS Code, Neovim and Obsidian. The trade-off is where your text goes. Cloud checkers send everything you type to a server, which matters for contracts, client work or unpublished manuscripts, while Harper and self-hosted LanguageTool keep text on your machine. Then check the character caps: a 500-word limit is fine for an email and painful for an essay. Run the same paragraph through two checkers before you pick, because they disagree on commas and style more than on real errors, and treat every suggestion as optional.

Grammarly

Free plan: spelling and grammar help, tone suggestions and 100 AI prompts, on web, desktop, mobile and browser. Pro is $12 a month.

Price: Free (Free plan with spelling and grammar help, tone suggestions and 100 AI prompts); paid from $12 per month (Pro; check the pricing page for the billing term) (Grammarly pricing, checked 2026-10-22).

Platforms and license: Web, Browser extension, Desktop app, Mobile app. Proprietary.

Best for: The most polished everyday checker.

Compare: Grammarly alternatives

LanguageTool

LGPL-2.1 core you can self-host, 25+ languages. Free plan limits text fields to 2,000 characters and 3 AI rephrasings a day.

Price: Free (Free plan with 2,000 characters per text field and 3 AI sentence rephrasings a day); paid from $5.83 per month, billed annually ($24.90 billed monthly, Premium) (LanguageTool pricing, checked 2026-10-22).

Platforms and license: Web, Browser extension, macOS, Windows, Self-hosted. LGPL-2.1 (open source).

Project activity: 15.2k GitHub stars · last commit Oct 27, 2026

Best for: Multilingual writing and privacy.

Worth knowing: The open-source core can be run as your own server for 25+ languages.

Harper

Apache-2.0, runs locally, English only, with plugins for VS Code, Neovim, Helix, Emacs, Zed and Obsidian. No paid tier listed.

Price: Free (open-source grammar checker that runs locally, no paid tier listed) (Harper pricing, checked 2026-10-22).

Platforms and license: Browser extension, Editor plugins, Self-hosted. Apache-2.0 (open source).

Project activity: 17.2k GitHub stars · latest release v3.0.0 (Oct 27, 2026) · last commit Oct 27, 2026

Best for: Private checking inside editors.

Worth knowing: English only; plugins cover VS Code, Neovim, Helix, Emacs, Zed and Obsidian.

ProWritingAid

Free plan gives suggestions for up to 500 words at a time with a few AI runs a day. Premium is $10 a month billed yearly.

Price: Free (suggestions for up to 500 words at a time with a few AI runs a day); paid from $10 per month, billed yearly ($120 a year; $30 billed monthly; lifetime $399) (ProWritingAid pricing, checked 2026-10-22).

Platforms and license: Web, Browser extension. Proprietary.

Best for: Style reports for fiction and essays.

Sapling

Free plan offers basic writing help and AI detector checks up to 2,000 characters per check. Pro is $12 a month billed annually.

Price: Free (basic writing assistance and AI detector checks up to 2,000 characters per check); paid from $12 per month, billed annually ($25 billed monthly, Pro) (Sapling pricing, checked 2026-10-22).

Platforms and license: Web, Browser extension. Proprietary.

Best for: Short messages and support replies.

Wordtune

Basic plan: 10 rewrites and AI suggestions a day, unlimited spelling and grammar checks. Advanced is $4.89 a month billed annually.

Price: Free (Basic plan with 10 rewrites and AI suggestions a day, 3 AI summaries a month and unlimited spelling and grammar checks); paid from $4.89 per month, billed annually (Advanced) (Wordtune pricing, checked 2026-10-22).

Platforms and license: Web, Browser extension. Proprietary.

Best for: Rewriting sentences.

QuillBot

Free tier exists and pairs grammar checks with a paraphraser. Check the Premium page for current limits and prices.

Price: Free (QuillBot pricing, checked 2026-10-23).

Platforms and license: Web, Browser extension. Proprietary.

Best for: Paraphrasing alongside grammar.

Compare: QuillBot alternatives

Which one to pick

• You want the best general checker and do not mind the cloud: Grammarly
• You write in several languages: LanguageTool
• Your text must stay on your machine: Harper
• You write long-form fiction or essays: ProWritingAid