AI grammar checker
What the AI grammar checker does
This AI grammar checker reads your text the way a careful editor would, rather than matching it against a fixed list of rules. Paste in a paragraph from ChatGPT, Claude, Gemini, Grok, DeepSeek or your own draft and it finds grammar, spelling and punctuation problems, then explains each one in plain language instead of just underlining it in red.
It is a server tool. Your text is sent to our server, a language model reads it and sends back the findings, and you get 5 free checks in any rolling 24 hours. Nothing you paste is stored afterward.
The difference from a rule-based checker matters more than it sounds. A model reading the sentence catches a subject and verb that stopped agreeing three clauses later, or a pronoun that no longer points at anything, the kind of mistake that is grammatically invisible to a fixed dictionary because no single word is misspelled.
The problem
Grammar mistakes in AI-written text, in plain terms
AI-generated text rarely has the errors people expect from a first draft: misspelled words, wrong verb tenses, obvious typos. What it does have is subtler and harder for a spellchecker to catch, because every word on its own is spelled correctly and every clause is grammatical in isolation.
The mistakes cluster in long sentences: a compound sentence joined by a comma instead of a conjunction, a modifier that drifted away from the noun it was supposed to describe, an aside inserted mid-sentence that quietly changes whether the verb should be singular or plural.
How it works
How to check AI grammar in three steps
No setup, no file to prepare. Paste, run, read the explanation.
- Step 1
- Paste the text you want checked, up to 12,000 characters. A full paragraph gives the checker more sentence structure to read than a single line does.
- Step 2
- Press Check text. It goes to our server once, a language model reads it for grammar, spelling and punctuation, and the findings come back to the page.
- Step 3
- Read each flagged issue and the reason given for it, then decide what to fix. Nothing is changed automatically.
Why it matters
What a rule-based grammar checker actually misses
A classic grammar checker works from a fixed dictionary of rules: it knows what a comma splice looks like and what subject-verb agreement requires, and it checks your sentence against that list. That catches a lot, but it cannot read the sentence for meaning, so it misses a pronoun that used to refer to something and no longer does after an edit, or a tense that quietly shifts halfway through a paragraph.
A language model reading the same sentence is doing something closer to comprehension. It notices when a sentence technically parses but doesn't actually say what the rest of the paragraph needs it to say. That is also exactly why it can be wrong in the other direction sometimes, stating a stylistic preference as if it were a rule. Both things are true, and it is worth saying so plainly.
The mechanism
Why a language model checks grammar differently than a rule engine does
A rule-based checker pattern-matches against grammar it was explicitly taught. A language model was trained on enormous amounts of ordinary writing, so it has an implicit sense of what a sentence in that position usually sounds like, and it flags the sentence that breaks that expectation even when no single rule in a textbook was technically broken.
That is a genuine strength on long or complicated sentences, the kind AI writing produces often, where an error hides three clauses deep. It is also the source of the tool's real limitation: a model's sense of what sounds right can be a preference dressed up as a correction, so treat every flag as a suggestion to weigh, not an automatic edit.
Straight answer
Does it catch every grammar mistake?
No, and a tool that claimed otherwise would be overselling itself. A language model reading for grammar can miss an error it has no strong expectation about, and it can occasionally flag a sentence that was actually fine, particularly an unusual but correct construction.
Treat the result as a strong first pass, not a guarantee. It will catch a great deal that a fixed-rule checker misses in AI-generated prose specifically, long sentences with a drifted subject or a tense that slips, but a final read by a human eye is still worth doing on anything that matters.
Who uses it
Who uses the AI grammar checker, and when
One check, several different reasons to run it before anything ships.
- Content editors
- Running AI-drafted copy through before it reaches a CMS, catching agreement and tense slips a spellchecker passed over.
- Students
- Checking an AI-assisted draft for the kind of grammar mistake that survives a normal spellcheck untouched.
- Non-native English writers
- Getting a plain-language explanation of why a sentence reads wrong, not just a red underline with no reason attached.
- Anyone editing a long document
- Catching the errors that hide in long sentences, where a subject and its verb drift apart across several clauses.