AI grammar checker
What the AI grammar checker does
This app runs a grammar check that reads your draft rather than pattern-matching it. Drop in something ChatGPT, Claude, Gemini, Grok or DeepSeek wrote, or your own text, and it finds grammar, spelling and punctuation problems, then tells you why each one is a problem instead of just underlining it.
It runs as a server tool: text goes to our server, a language model reads it, and the findings come back to the page. 5 free checks in any rolling 24 hours, no account required.
That matters for a team pushing AI-assisted drafts through a publishing workflow. Rule-based checkers built into most editors miss the mistakes that hide in long, AI-generated sentences, because every individual word is spelled right. A model reading for meaning catches those.
The problem
Grammar mistakes in AI drafts, in plain terms
AI output rarely misspells a word. What it does is subtler: a subject and its verb drift apart across an inserted aside, a pronoun stops matching what it used to refer to, a modifier ends up describing the wrong noun. None of it trips a spellchecker.
- Agreement drift
- A subject set up early in a long sentence, with the verb landing after an aside that quietly changed whether it should be singular or plural.
- Dangling references
- A pronoun that used to point somewhere and no longer does, usually after a clause got reordered or trimmed.
- Comma splices
- Two complete sentences joined with just a comma, common in the run-on rhythm long AI answers fall into.
- Misplaced modifiers
- A qualifying phrase sitting next to the wrong noun, technically parseable but not saying what it means to.
Workflow
How to check an AI draft's grammar in three steps
Three steps, no prep work.
- 1. Paste the draft
- Drop in the text you're checking, up to 12,000 characters. More text gives the check clearer sentence structure to read.
- 2. Run the check
- The text goes to our server once, gets read for grammar, spelling and punctuation, and the flags come back to the page.
- 3. Read the reasoning
- Each flag ships with a plain-language reason. Use it to decide what actually needs a fix before you publish.
Why it matters
What a fixed-rule grammar checker misses in an AI draft
Most editors already run a built-in grammar checker, and it's working from a fixed rule set: known patterns for agreement, known patterns for punctuation. That catches typos and the obvious stuff, but it can't tell that a pronoun no longer refers to anything, because nothing about the sentence in isolation looks wrong.
A language model reading the whole passage catches that class of error specifically, because it is tracking what the sentence is actually trying to say, not just whether it parses. The honest trade is that it can occasionally be wrong the other way, calling out an unusual but correct sentence.
The mechanism
Why this checker works differently from the one built into your editor
A built-in checker was taught explicit rules. This one was trained on a huge amount of ordinary writing, so it has a working sense of what a sentence in this position usually sounds like, and flags a break from that even when no formal rule was technically violated.
That's especially useful on the long, clause-stacked sentences AI drafts tend to produce, where an error sits three clauses in. It's also why a flag here is a suggestion to weigh, not an instruction to apply without reading it first.
Straight answer
Does it catch everything before you publish?
No. It catches a lot that a fixed-rule checker misses, particularly in long AI-generated sentences, but it can also miss something it has no strong expectation about, or flag a correct sentence that just reads unusually.
Use it as a strong pass before a human editor's final read, not a replacement for one, on anything that's actually going to ship.
Who uses it
Who runs the AI grammar checker before publishing
Same check, different points in a workflow.
- Content teams
- Running AI-drafted copy through before it reaches the CMS, catching agreement and tense slips a built-in checker passed over.
- Agencies
- Adding a check between an AI-assisted first draft and the version a client sees.
- Support teams
- Reviewing AI-drafted replies for a grammar slip before a customer reads it.
- Students and writers
- Getting a plain explanation of why a sentence reads wrong, not a red underline with no reason given.