Best Free AI Grammar Checkers

What Free Grammar Checkers Actually Include

Free grammar checkers are not crippled demos. The best free tiers catch the errors that matter most in everyday writing: misspellings, grammatical mistakes, punctuation errors, and the most common homophones (your/you're, its/it's, their/there/they're). What free tiers typically exclude are style-level suggestions (tone detection, wordiness reduction, clarity improvements), full-sentence rewrites, plagiarism checking, and advanced consistency analysis. For writers who need their text to be correct rather than polished, a free grammar checker is often sufficient.

The real tradeoff in most free tiers is volume, not features. Grammarly Free has no word limit but restricts the types of suggestions you see. LanguageTool Free limits each check to 10,000 characters. QuillBot Free has no limits at all on grammar checking, though its paraphrasing tool is restricted. Understanding these limits helps you choose the free tier that fits your writing volume and workflow.

1. Grammarly Free: Best Overall Free Grammar Checker

Grammarly's free tier catches spelling errors, basic grammar mistakes, and punctuation problems across every platform where Grammarly's extensions work. That includes Gmail, Google Docs, Microsoft Word (via the desktop app), Slack, LinkedIn, Twitter/X, and essentially every text field in Chrome, Firefox, Edge, and Safari. The detection quality on basic errors is identical to the Premium tier, meaning you get Grammarly's full accuracy on the error categories that the free plan covers.

What the free tier excludes are the style-level features that define the Premium experience: clarity suggestions, tone detection, formality level adjustment, full-sentence rewrites via GrammarlyGO, vocabulary enhancement, and plagiarism checking. For a writer sending business emails, drafting social media posts, or typing messages in Slack, the free tier catches the errors that would make the writer look careless without any cost. The absence of style coaching means the writing will be correct but may not be as polished as it could be with Premium suggestions.

Grammarly Free also includes a basic writing score that summarizes overall quality, but without Premium, the score is based only on correctness rather than the full range of style, engagement, and delivery metrics. There is no daily check limit, no character limit per check, and no restriction on the number of devices where the extension is installed.

2. LanguageTool Free: Best for Multilingual Writers

LanguageTool's free tier is the most feature-complete free grammar checker for writers who work in multiple languages. It supports grammar checking in over 30 languages, including English, German, French, Spanish, Portuguese, Dutch, Polish, Russian, Catalan, and many others. Each language has its own dedicated set of grammar rules maintained by native-speaker linguists, not just a spell-check dictionary with a translated interface.

The free tier checks up to 10,000 characters per request, which covers most individual documents, emails, and assignments. For a 2,000-word essay (approximately 12,000 characters), you would need to check it in two parts, which is mildly inconvenient but workable. The detection covers grammar, spelling, punctuation, and some basic style issues like repeated words and wordy phrases. It misses the more advanced style suggestions available in the Premium "picky mode" but catches the errors that most writers need fixed.

The browser extension works in Chrome, Firefox, Edge, Safari, and Opera. LanguageTool also integrates directly with Google Docs, Microsoft Word (via an add-in), and LibreOffice. The extension does not require account creation for basic use, which is unusual among grammar checkers, meaning you can install it and start checking immediately without providing an email address. For privacy-conscious users, this matters.

The open-source nature of LanguageTool means that its grammar rules are publicly visible on GitHub. Users who encounter a false positive or a missed error can file an issue or even submit a correction themselves. This community-driven approach has resulted in an exceptionally thorough rule set for several languages, particularly German, where LanguageTool is widely considered the best grammar checker available.

3. QuillBot Grammar Checker Free: Most Generous Limits

QuillBot offers the most generous free grammar checking of any tool reviewed here: unlimited checks, no character limit per check, and no daily restriction. You can paste an entire 10,000-word document and check it for free, which no other major grammar checker allows without requiring a paid plan or splitting the text into smaller chunks.

The detection quality covers spelling, grammar, and punctuation errors but does not extend to style suggestions, tone detection, or contextual improvements in the free tier. QuillBot caught 80% of errors in standardized testing, which is lower than Grammarly (94%) or LanguageTool (87%), meaning it will miss some errors that other tools catch. The errors it misses tend to be the more subtle ones: comma placement in complex sentences, advanced subject-verb agreement with intervening clauses, and some contextual word choice errors.

The major advantage of QuillBot's free tier is its integration with the rest of QuillBot's writing toolkit. After grammar checking, you can use the free paraphraser (limited to Standard and Fluency modes in the free tier) to rephrase awkward passages, or use the summarizer to condense research material. For students and academic writers who use QuillBot for multiple writing tasks, having grammar checking included for free alongside these other tools creates a useful combined workflow.

4. Microsoft Editor: Best for Microsoft 365 Users

Microsoft Editor is built into Microsoft Word, Outlook, and Edge, making it the default grammar checker for anyone who works within the Microsoft ecosystem. The free tier covers spelling, basic grammar, and punctuation across these platforms, with a browser extension for Edge and Chrome that extends coverage to web-based writing. For writers who already use Microsoft 365, Editor requires no additional installation or account creation.

Microsoft Editor's grammar detection is solid for basic errors but less sophisticated than Grammarly or LanguageTool on contextual corrections. It handles homophones, subject-verb agreement, and capitalization well, but its style suggestions are limited and occasionally generic. The tool benefits from Microsoft's investment in AI through Copilot integration in premium Microsoft 365 plans, but the free tier does not include Copilot's advanced rewriting capabilities.

The main advantage of Microsoft Editor is zero friction for existing Microsoft users. It works immediately in Word and Outlook without installing an extension, downloading an app, or creating a separate account. For writers whose workflow is entirely within Microsoft's ecosystem, Editor provides adequate grammar checking without adding another tool to the stack.

5. Google Docs Built-In: Best for Google Workspace Users

Google Docs includes a built-in grammar checker that has improved significantly with AI enhancements. The tool catches spelling errors, basic grammar mistakes, and some style issues like passive voice and wordy phrasing. Suggestions appear as blue underlines (for grammar) and red underlines (for spelling), with corrections available via right-click or the "Tools > Spelling and Grammar" menu.

The detection quality is adequate for basic errors but trails dedicated grammar checkers by a meaningful margin. Google's grammar checker is less accurate on complex sentence structures, comma placement in compound sentences, and contextual word choice than Grammarly or LanguageTool. It also offers no style coaching, tone detection, or document-level consistency analysis.

The advantage is that it requires nothing: no installation, no account beyond the Google account you already have, and no cost. For writers who work primarily in Google Docs and need basic error checking, the built-in tool covers the fundamentals. Writers who need deeper correction can install the Grammarly or LanguageTool extension for Google Docs and get both tools working in the same document simultaneously.

6. Hemingway Editor: Best for Readability

Hemingway Editor is not a traditional grammar checker but a readability analyzer that highlights problematic patterns in your writing. It color-codes sentences by issue type: yellow for hard-to-read sentences, red for very hard-to-read sentences, purple for words with simpler alternatives, blue for adverbs, and green for passive voice. The tool assigns an overall readability grade level and encourages writers to aim for grade 9 or lower for general audiences.

The web version at hemingwayapp.com is completely free with no account required. You paste your text and immediately see the highlighted analysis. Hemingway does not fix errors automatically or offer specific corrections. Instead, it identifies patterns that make writing harder to read and leaves the revision decisions to the writer. This makes it a complement to a grammar checker rather than a replacement: use Grammarly or LanguageTool to fix errors, then paste the corrected text into Hemingway to identify readability improvements.

The desktop app ($19.99, one-time purchase) adds file management and the ability to publish directly to WordPress and Medium. The web version provides the same analysis engine for free. Hemingway is particularly useful for content writers, bloggers, and marketers who need their writing to be accessible to broad audiences.

How to Get the Most From Free Grammar Checkers

The strongest free setup combines two tools that complement each other. Install Grammarly Free as your primary browser extension for real-time error catching across all platforms. Use LanguageTool Free for checking longer documents that benefit from its character-based checking model, or for any writing in languages other than English. Add Hemingway Editor as a final pass for readability when writing content meant for general audiences.

This combination catches more errors than any single free tool and covers the most important quality dimensions: correctness (Grammarly), thoroughness for longer texts (LanguageTool), and readability (Hemingway). The only overlap is in basic English grammar checking, where having two tools occasionally catch the same error is harmless. The gaps, primarily style coaching, tone detection, and full-sentence rewrites, are the features that paid plans deliver and that justify upgrading when the free tools feel insufficient.

One important consideration: running multiple grammar checker extensions simultaneously can cause conflicts in some web applications. If you notice duplicate suggestions, slow typing response, or missing underlining, disable one extension and rely on the other for that particular site. Grammarly and LanguageTool generally coexist without problems in most environments, but rare conflicts can occur in complex web editors.