AI Tools

Free Grammar Checker Online — Grammar, Spelling, Style & Passive Voice

The most advanced free grammar checker available. Powered by LanguageTool's engine of 6,000+ linguistic rules, it catches grammar errors, spelling mistakes, punctuation issues and style problems in seconds — the same engine used by over 10 million people worldwide via the LanguageTool browser extension.

Includes unique features: writing goals, error breakdown chart, passive voice detector, adverb scanner, overused word finder and tone analysis.

Unlike Grammarly (paid for advanced features) or Hemingway (style-only), PursTech's grammar checker combines LanguageTool's rule engine with unique client-side analytics — all free, no account required. See how it compares in the feature table below.

Writing Goal
Powered by LanguageTool · 6,000+ rules · free, no account
492/20000

Text Analysis

Words80
Sentences6
Issues0
Error density0/100w
TonePositive
Readability83/100 · Easy

Passive Voice

1 found
was completed

Active voice is clearer — rewrite passive constructions where possible.

Adverbs (-ly)

5 found
firstlyeffectivelyquicklysignificantlybasically

Replace adverbs with stronger verbs for more vivid writing.

Overused Words

0 flagged
✓ No words used excessively

Words used 3+ times — consider synonyms to vary your vocabulary.

📐6 Writing Goal Presets

Set your writing purpose — Email, Essay, Blog, Business, Creative or General — and get targeted feedback for your audience.

🥧Error Breakdown Chart

SVG donut chart shows the exact split of grammar, spelling, punctuation and style issues at a glance.

🔕Passive Voice Detector

Client-side scanner highlights passive voice constructions independently of LanguageTool, so you can spot and rewrite them.

📊Overused Word Finder

Word frequency analysis identifies words you've repeated too many times — a key sign of weak, repetitive writing.

🎭Tone Detector

Detects whether your writing is formal or casual, positive or critical — based on vocabulary patterns.

📝Error Density Score

Errors per 100 words — a normalised measure that lets you compare quality fairly regardless of document length.

Who uses this tool?

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StudentsCheck essays and assignments for grammar, spelling and academic style before submission.
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Content WritersProof blog posts and articles — catch passive voice, adverbs and overused words that weaken copy.
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Non-native SpeakersLanguageTool's 6,000+ rules catch subtle English errors that basic spell-checkers miss entirely.
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Business ProfessionalsPolish emails and reports — correct tone, eliminate errors and ensure professional quality.

PursTech vs Grammarly vs Hemingway vs LanguageTool

Feature comparison — all at zero cost

FeaturePursTechGrammarlyHemingwayLanguageTool
Grammar & spelling✓✓—✓
In-text colour highlights✓✓✓✓
Writing goal presets✓✓——
Error breakdown chart✓———
Passive voice detection✓Paid✓✓
Overused word finder✓———
Tone detector✓Paid——
Error density score✓———
Adverb scanner✓—✓—
Download error report✓———
Multi-language support✓——✓
100% free, no account✓——✓

How to Use the Grammar Checker

1
Set your writing goal
Pick Email, Essay, Blog, Business, Creative or General to get feedback tailored to your text's purpose and audience.
2
Paste your text
Enter up to 20,000 characters. The sample text shows exactly what the tool catches so you can see it in action immediately.
3
Check and review
Click Check Grammar or press Ctrl+Enter. LanguageTool analyses your text and highlights errors colour-coded by type. Hover any highlight for the explanation.
4
Fix and export
Click individual replacements to fix one at a time, or hit Fix All to apply every correction instantly. Download the full error report as .txt.

❓ Frequently Asked Questions

What grammar rules does LanguageTool check and how is it different from a spell-checker?+
A basic spell-checker only flags words not found in its dictionary. LanguageTool goes much further — it analyses the grammatical structure of each sentence to catch errors a dictionary can't detect: Grammar errors: Subject-verb disagreement ("The team are playing" vs "The team is playing"), wrong tense, incorrect pronoun case ("between you and I" → "between you and me"), dangling modifiers, split infinitives. Spelling errors: Misspelled words, including confusable homophones ("their/there/they're", "affect/effect", "its/it's") that a simple spell-checker would miss because both words exist. Punctuation errors: Missing commas after introductory clauses, incorrect apostrophe use, run-on sentences, missing Oxford commas. Style suggestions: Passive voice, wordy phrases ("in order to" → "to"), clichés, redundant intensifiers ("very unique"), double negatives, informal language in formal contexts. LanguageTool maintains over 6,000 rules for English and operates in over 30 languages, making it one of the most comprehensive free grammar engines available.
What are writing goals and which one should I choose?+
Writing goals help focus the grammar checker's feedback on what matters most for your specific type of text: 📧 Email — Prioritises clarity and conciseness. Flags overly long sentences and formal language that feels cold for email context. Good for business emails, customer support and newsletters. 🎓 Essay — Applies academic writing standards. Flags informal contractions, first-person overuse (in formal essays) and imprecise language. Good for university assignments and academic papers. 📰 Blog Post — Balances readability with engagement. Flags passive voice and complex sentences that hurt web readability scores. Good for content marketing. 💼 Business — Professional formal tone. Flags ambiguous language, hedging words and unclear structure. Good for reports, proposals and presentations. 🎨 Creative — Relaxes many style rules intentionally broken in fiction, poetry and creative non-fiction. Still catches genuine grammar errors. 📝 General — All rules active with equal weight. Best when you're unsure.
What is passive voice, why is it flagged, and when is it acceptable?+
Passive voice occurs when the sentence's subject receives the action rather than performing it: Active: "The manager approved the budget." (subject acts) Passive: "The budget was approved by the manager." (subject receives action) Why it's flagged: Passive voice adds words without adding meaning. "The budget was approved" is 4 words; "The manager approved the budget" is 5 words but tells you who did it. Excessive passive voice makes writing feel bureaucratic, evasive and harder to follow. When passive voice is acceptable: • When the actor is unknown: "The package was stolen." • When the actor is unimportant: "The data was collected over six months." • Scientific writing, where the method matters more than who performed it: "The samples were centrifuged at 3000 rpm." • Formal policy writing: "Employees are required to..." Rule of thumb: If you can name who did the action and it adds value, use active voice. If the actor is irrelevant or unknown, passive is fine.
What are adverbs and why does the checker flag them?+
Adverbs modify verbs, adjectives or other adverbs. Many end in -ly: quickly, slightly, extremely, honestly, basically, literally. The checker flags -ly adverbs as a writing quality reminder — not as hard errors. Why adverbs can weaken writing: An adverb is often a sign that the verb or adjective it modifies isn't strong enough. "He ran quickly" can become "He sprinted." "She was extremely happy" can become "She was ecstatic." Replacing an adverb with a stronger, more specific word almost always produces clearer, more vivid writing. Adverbs to watch especially: • "Very" and "really" — almost always replaceable: "very important" → "critical"; "really fast" → "rapid" • "Basically," "essentially," "literally" used as filler at the start of sentences • Adverbs that contradict the verb: "smiled happily," "shouted loudly" — the verb already implies the adverb When adverbs are fine: technical writing, dialogue ("she said quietly"), and cases where the specific degree genuinely matters.
How does the overused word finder work and what should I do about it?+
The overused word finder counts how many times each significant word (4+ letters, excluding common stop words like "the", "that", "with") appears in your text. Words appearing 3 or more times are flagged. Why word repetition matters: Repeating the same word within a short passage is one of the most common and easiest-to-fix signs of weak writing. It's especially noticeable to readers even if they don't consciously identify it. What to do with flagged words: 1. Check if the repetition is intentional: rhetorical repetition for emphasis is a valid stylistic choice. 2. If not intentional, find synonyms. Use a thesaurus for the most repeated words. 3. Sometimes repetition can be eliminated by restructuring the sentence entirely. 4. Some technical documents legitimately repeat key terms for precision and shouldn't be paraphrased. Common offenders: "important," "significant," "use," "provide," "ensure," "process," "approach." These are vague placeholder words that often indicate the sentence could be more specific.

Why Good Grammar Matters — and How to Improve It

Grammar is the foundation of clear communication. Poor grammar erodes reader trust, reduces perceived authority and makes content harder to understand. Studies in content marketing consistently show that grammar errors increase bounce rates and reduce conversion — readers associate errors with low quality, whether they consciously notice them or not. For professional communication, this is especially critical: a single apostrophe error in a business proposal can undermine confidence in an otherwise strong pitch.

For non-native English speakers, grammar checkers are particularly valuable. English has many traps — articles (a/an/the), prepositions, verb conjugation and countable vs uncountable nouns all differ from most other language families. LanguageTool's rules were developed specifically to catch the patterns that non-native speakers most frequently get wrong, making it significantly more useful than a standard spell-checker for English as a second language writing.

Beyond grammar, writing quality depends on style: sentence variety, active voice, precise vocabulary and appropriate tone for your audience. The best writers don't just avoid errors — they actively choose words and structures that create clarity and engagement. Using a grammar checker as a first pass, then reviewing the style suggestions, passive voice and overused word analysis gives you a comprehensive review that approximates what a professional editor would catch.