GrammarPro vs Grammarly vs LanguageTool — Free Tier Comparison

The Free Grammar Checker Landscape

Everyone needs a grammar checker, but not everyone wants to pay $12/month for one. We tested the free tiers of three popular tools to see what you actually get without opening your wallet.

GrammarPro — Best Free Option

GrammarPro is a free, browser-based grammar checker powered by AI.

What you get for free:

• Full grammar, spelling, and punctuation checking
• Style and clarity suggestions
• Tone analysis
• No word limits
• No signup required
• Works entirely in your browser

What's missing: Nothing — all features are free.

Privacy: Text is processed using AI but GrammarPro doesn't store your content. No account means no data profile.

Best for: Anyone who wants a full-featured grammar checker without paying or creating an account.

Grammarly — Most Popular, Limited Free Tier

Grammarly is the most well-known grammar checker, but its free tier is surprisingly limited.

What you get for free:

• Basic grammar and spelling corrections
• Punctuation fixes
• Browser extension, desktop app, mobile keyboard

What's locked behind Premium ($12/month):

• Clarity and conciseness suggestions
• Tone adjustments
• Word choice improvements
• Plagiarism detection
• Full-sentence rewrites
• GrammarlyGO AI assistant

Privacy: Grammarly processes text on their servers. They state they don't sell data, but your text is transmitted for processing.

Best for: Users who only need basic spell-check and are willing to pay for advanced features.

LanguageTool — Best for Multiple Languages

LanguageTool is an open-source grammar checker that supports 30+ languages.

What you get for free:

• Grammar and spelling in 30+ languages
• Basic style suggestions
• 10,000 characters per check
• Browser extension

What's locked behind Premium ($4.99/month):

• 150,000 characters per check
• Advanced style suggestions
• Picky mode (catches more subtle issues)
• Add-on for Word and Google Docs

Privacy: Open-source core means you can self-host. The online version processes text on their servers but has a strong privacy policy.

Best for: Multilingual writers or anyone who wants an open-source option.

Head-to-Head: What Matters

Accuracy on English Text

We tested all three with a 500-word passage containing 15 intentional errors (grammar, punctuation, style, and spelling).

• GrammarPro: Caught 14/15 errors, plus 3 style suggestions
• Grammarly Free: Caught 12/15 errors (missed style issues — those are Premium)
• LanguageTool Free: Caught 11/15 errors, plus 2 style notes

Speed

• GrammarPro: Instant (under 2 seconds)
• Grammarly: Fast (2-3 seconds via extension)
• LanguageTool: Fast (2-3 seconds)

Character/Word Limits

• GrammarPro: No limits
• Grammarly Free: No hard limit but nags for Premium
• LanguageTool Free: 10,000 characters per check

Ease of Use

All three are easy to use. Grammarly has the most polished interface. GrammarPro has the lowest friction — no account needed, just paste and check. LanguageTool requires a quick signup for the extension.

The Verdict

For a completely free, full-featured grammar checker, GrammarPro wins. You get everything — grammar, style, tone, clarity — without limits or signup.

Grammarly is worth it if you're willing to pay $12/month for the Premium tier. The free version is too limited for serious writing.

LanguageTool is the pick for multilingual writers or anyone who values open-source software. Its free tier is more generous than Grammarly's.

Our recommendation: start with GrammarPro (it's free and instant), and upgrade to a paid tool only if you need specific features like plagiarism detection or 30-language support.