I ran the same 2,000-word blog draft through 8 different grammar checkers last month. The draft had 23 intentional errors – comma splices, subject-verb disagreements, dangling modifiers, and a few tricky ones like “who” vs “whom” misuse. The results varied wildly. One tool caught 21 out of 23. Another found only 9 and flagged 4 false positives on top of that.
If you’re looking for a full comparison of grammar tools with features and pricing, check out our best grammar checkers roundup. This guide focuses on the practical how-to: which free tools actually work, what their limits are, and how to get the best results without paying.
Quick Comparison: Free Grammar Checking Tools
| Tool | Free Limit | Languages | Errors Caught (out of 23) | False Positives | Best For |
|---|---|---|---|---|---|
| Grammarly | Unlimited basic checks | English only | 21 | 1 | Overall accuracy |
| LanguageTool | 10,000 chars/check | 30+ | 18 | 2 | Non-English writers |
| Microsoft Editor | Unlimited (browser ext.) | English + 20 | 16 | 1 | Microsoft ecosystem users |
| QuillBot | Unlimited grammar checks | English only | 15 | 3 | Grammar + paraphrase combo |
| Hemingway Editor | Unlimited (web) | English only | 12 | 0 | Readability and clarity |
| Google Docs | Unlimited | English + 8 | 14 | 2 | Already in your workflow |
| Scribens | Unlimited | English, French | 13 | 4 | Quick anonymous checks |
1. Grammarly Free – Best Overall Accuracy
Grammarly’s free tier caught 21 of my 23 planted errors. It missed a subtle dangling modifier and one comma splice in a compound-complex sentence. Only one false positive – it flagged a sentence fragment I used intentionally for emphasis.
How to use it:
- Go to grammarly.com and create a free account (Google sign-in works)
- Open the web editor and paste your text
- Errors show up underlined in red – click each one for the suggested fix
- Accept or dismiss suggestions individually
The browser extension is where Grammarly gets really useful. Install it in Chrome, Firefox, or Edge and it checks grammar everywhere you type – Gmail, social media, forms, anywhere. No copy-pasting needed.
Free tier limits:
- Catches spelling, grammar, and punctuation errors
- No style suggestions, tone detection, or plagiarism checks on free
- No word choice improvements (that’s Premium at $12/month)
- Works on desktop and mobile (iOS/Android keyboards)
Where it falls short:
- Requires an account – no anonymous checking
- English only on the free plan
- The constant Premium upsell banners get annoying
2. LanguageTool – Best for Non-English Text
LanguageTool is open-source and supports over 30 languages. My English test showed 18 out of 23 errors caught. It missed some of the more nuanced grammar issues – specifically the “who/whom” distinction and two comma placement errors that even some paid tools struggle with.
Where LanguageTool shines is multilingual support. I tested it with German and Spanish text, and it caught errors that Grammarly can’t even attempt. If you write in multiple languages, this is your tool.
How to use it:
- Go to languagetool.org – no account needed for basic checks
- Paste text directly into the editor (10,000 character limit per check)
- Colored underlines indicate different error types – blue for style, red for grammar, orange for potential issues
- Click each underline for explanation and fix
Free tier limits:
- 10,000 characters per check (about 1,500 words)
- Basic grammar, spelling, and some style suggestions
- Browser extension available for Chrome and Firefox
- LibreOffice and Google Docs add-ons available
Where it falls short:
- 10K character cap means you need to split longer documents
- Less accurate on English than Grammarly (missed 5 vs Grammarly’s 2)
- Advanced style suggestions locked behind Premium ($4.99/month)
Also worth noting – there’s a self-hosted version if you care about privacy. You can run the full LanguageTool server on your own machine. Takes about 15 minutes to set up with Docker.
3. Microsoft Editor – Best if You Already Use Edge or Word
Microsoft Editor is a browser extension that does grammar checking anywhere you type online. It caught 16 of my 23 errors. Not the highest score, but the integration makes up for it if you’re already in the Microsoft ecosystem.
The free version handles spelling and basic grammar. What I like is that it works silently – no popups, no account prompts, just quiet underlines when you make a mistake. It checks grammar in real time as you type, similar to what Word does on desktop.
How to use it:
- Install the Microsoft Editor extension from the Chrome Web Store or Edge Add-ons
- Sign in with a Microsoft account (free Outlook/Hotmail account works)
- Start typing anywhere online – errors get underlined automatically
- Right-click underlined text for correction options
Free tier limits:
- Spelling and basic grammar corrections
- Works across most websites and text fields
- Supports 20+ languages for spell checking
Where it falls short:
- Advanced refinements (clarity, conciseness, formality) need Microsoft 365 ($6.99/month)
- Missed 7 of 23 errors – weaker on punctuation rules than Grammarly
- Occasionally conflicts with other grammar extensions if you have multiple installed
4. QuillBot Grammar Checker – Best for Checking + Rewriting
QuillBot caught 15 errors out of 23, which puts it in the middle of the pack. But the grammar checker is just one piece. The real value is the combo – check grammar, then paraphrase sections that sound clunky, all in one tab. We covered the paraphrasing side separately in our how to paraphrase text guide.
How to use it:
- Go to quillbot.com/grammar-check
- Paste your text (no character limit for grammar checking)
- Click “Check Grammar” – errors highlighted with suggestions
- Switch to the Paraphraser tab if you want to rework sentences
The 3 false positives I got were all stylistic preferences, not real errors. QuillBot flagged passive voice as a “grammar issue” which is debatable. Passive voice isn’t wrong – it’s a choice.
Free tier limits:
- Unlimited grammar checks
- 125-word limit on the paraphraser (free)
- Chrome extension available
- Summarizer and citation generator also free with limits
Where it falls short:
- English only
- Lower accuracy than Grammarly and LanguageTool on pure grammar
- The 125-word paraphraser limit is restrictive if you’re trying to rewrite paragraphs
5. Hemingway Editor – Best for Readability
Hemingway doesn’t try to be a grammar checker. It’s a readability tool that happens to catch some grammar mistakes along the way. It found 12 of my 23 errors, all of them basic – run-on sentences, passive voice, complex phrasing. It completely missed the who/whom errors, comma splices, and subject-verb issues.
But here’s the thing. Hemingway does something none of the others do well: it tells you when your writing is hard to read. Sentences get color-coded by difficulty. Yellow means “hard to read.” Red means “very hard to read.” You also get a readability grade (aim for Grade 9 or lower for web content).
How to use it:
- Go to hemingwayapp.com
- Paste or type your text – the web version is completely free
- The right sidebar shows stats: readability grade, sentence count, word count, reading time
- Color-coded highlights show problem areas
Zero false positives in my test. Every suggestion Hemingway made was valid. It doesn’t over-flag.
Free tier limits:
- Web editor is 100% free with no character limits
- No account needed
- Desktop app costs $19.99 (one-time, not subscription)
Where it falls short:
- Not a replacement for a full grammar checker – it catches maybe half of real grammar errors
- English only
- Can’t export directly from the web version (copy-paste only)
- No browser extension
I use Hemingway as a second pass. Run your text through Grammarly or LanguageTool first for grammar, then paste into Hemingway for readability. Takes an extra 2 minutes and catches different types of problems.
6. Google Docs Built-in Grammar Check
If you write in Google Docs, you already have a grammar checker. It caught 14 of my 23 errors without installing anything. Just type and the blue squiggly lines appear under grammar issues (red for spelling).
Google’s grammar check has gotten noticeably better in the past year. It now catches some subject-verb disagreement and awkward phrasing that it used to miss entirely. Still not as thorough as Grammarly, but the convenience factor is hard to beat.
How to use it:
- Open any Google Docs document
- Go to Tools > Spelling and grammar > Spelling and grammar check
- A panel opens showing each issue with Accept/Ignore buttons
- Or just right-click any underlined word for quick fix options
Free tier limits:
- No limits – works on any document, any length
- Works across 9 languages for grammar (more for spell-check)
- Autocorrect for common mistakes
Where it falls short:
- Requires Google Docs – can’t paste text into a standalone tool
- Missed 9 of 23 errors in my test, mostly punctuation and complex grammar
- No standalone browser extension for non-Docs writing
- Suggestions sometimes lack explanations (just “Consider revising” with no reason why)
7. Scribens – Best for Anonymous Quick Checks
Scribens requires no signup, no email, nothing. Open the website, paste text, get results. It caught 13 errors in my test, which is decent for a completely free tool with zero friction.
The downside: 4 false positives. Scribens flagged some correct British English spellings and a properly used semicolon. If you know your grammar well enough to dismiss bad suggestions, it’s fine. If you’re less confident, those false flags might confuse you.
How to use it:
- Go to scribens.com
- Paste your text in the editor
- Click the check button
- Errors shown with color coding and explanations
Free tier limits:
- No character limits advertised, but performance drops on very long texts (5000+ words)
- English and French only
- No account required
Where it falls short:
- Highest false positive rate in my test (4 out of 17 flags were wrong)
- No browser extension
- Interface feels outdated
- Only English and French
How to Get the Best Results from Free Grammar Checkers
After testing all these tools, a few things became obvious about getting accurate results.
Use two tools, not one. No single free grammar checker caught everything. Grammarly got 21/23, but even it missed two. Running your text through Grammarly first and LanguageTool second caught 22 of my 23 errors. The remaining one – a particularly subtle dangling modifier – none of the free tools found.
Don’t accept every suggestion blindly. Every tool in this list generated at least one false positive or questionable suggestion. QuillBot flagging passive voice as “wrong” is a good example. Passive voice is a style choice, not an error. If you accept every suggestion without thinking, your text might end up technically correct but lifeless.
Watch out for character limits. LanguageTool’s 10,000-character cap means you’ll need to split a 3,000-word article into two passes. Annoying, but still faster than manual proofreading. Copy sections logically – don’t split mid-paragraph or you’ll miss errors that depend on context from the previous sentence.
Check the explanation, not just the fix. Grammarly and LanguageTool both explain why something is flagged. Read those explanations. After a month of doing this, I noticed I was making fewer comma splice errors because I actually learned the rule from the explanations, not because the tool was catching them.
Free vs Paid: Is Upgrading Worth It?
Honest answer: for most people writing emails, blog posts, or school assignments, the free tiers are enough. Grammarly Free catches over 90% of common grammar errors. The premium features you’re missing are mostly style and tone suggestions.
When paid makes sense:
- You write professionally and need clarity, tone, and delivery suggestions (Grammarly Premium, $12/month)
- You write in multiple languages and hit the 10K character wall constantly (LanguageTool Premium, $4.99/month)
- You need plagiarism detection built into your grammar checker (Grammarly Premium or ProWritingAid at $10/month)
If you want alternatives to Grammarly specifically, we put together a list of free Grammarly alternatives that covers some options not in this guide.
For everyone else, the combination of Grammarly Free + Hemingway catches grammar errors and readability issues without spending a dollar.
FAQ
Is Grammarly free version good enough for professional writing?
For catching actual grammar and spelling mistakes, yes. Grammarly Free handles punctuation, subject-verb agreement, and common errors well. What you miss on free is style coaching – suggestions about tone, word choice, and sentence variety. If you’re writing marketing copy or client-facing documents, the paid version might be worth it. For internal emails, blog posts, and everyday writing, free handles it fine.
Can grammar checkers detect all types of errors?
No. None of the tools I tested caught every error. The biggest blind spots across all free tools: subtle dangling modifiers, ambiguous pronoun references, and logical inconsistencies (like “the temperature decreased by 20% to 50 degrees” when the math doesn’t work). Grammar checkers handle mechanical errors well but can’t fully evaluate meaning or intent.
Do free grammar checkers store or sell my text?
It depends on the tool. Grammarly’s privacy policy says they process text to deliver suggestions but don’t sell it to third parties. LanguageTool has a self-hosted option if privacy matters to you. Google Docs text stays in your Google account. For sensitive documents – legal, medical, financial – consider LanguageTool’s local server or Hemingway’s desktop app, both of which work offline.
Which free grammar checker works best for academic writing?
Grammarly Free for grammar accuracy, combined with Hemingway for readability. Academic writing has specific needs – proper citation style, formal tone, avoiding contractions – and no free tool handles all of those. Grammarly catches the grammar basics, Hemingway flags overly complex sentences (which academic writing is full of), and you still need to manually check citations and formatting against your style guide (APA, MLA, Chicago).
Can I use multiple grammar checkers at the same time?
You can, but be careful with browser extensions. Running Grammarly and Microsoft Editor extensions simultaneously can cause conflicts – double underlining, competing suggestions, and sometimes they’ll try to correct each other’s corrections. My recommendation: keep one extension active for day-to-day typing (Grammarly), and use a web-based tool (LanguageTool or Hemingway) as a second pass for important documents. Disable the extra extension rather than running both.