AI GPTZero checker
What the AI GPTZero checker does
This tool reads a piece of text and reports the writing patterns typical of AI-generated content, in particular the low-predictability, evenly-paced sentences that a perplexity-and-burstiness style checker looks for. It answers the question people search before pasting text anywhere else: will this look machine-written.
It's a server tool. Your text is sent to our AI server, scored against known AI-writing patterns, and the flagged signals come back to the page. You get 5 free checks in any rolling 24 hours, no account needed.
It has no access to GPTZero's own system and never rewrites your text. It names each pattern and explains it, rather than handing you a bare percentage.
How this kind of check works
What perplexity and burstiness actually measure
Perplexity is a measure of how predictable each next word is to a language model. Text where every word choice is the safest, most expected one scores low; text with more surprising, specific word choices scores higher. AI-generated text tends to sit on the low, predictable end.
Burstiness measures how much that predictability varies across a document. Human writing tends to burst, mixing short blunt sentences with long winding ones, plain stretches with sudden complexity. AI-generated text tends to stay flatter and more even from sentence to sentence. Neither measure proves anything alone; both are proxies, and imperfect ones.
How it works
How to check AI text against GPTZero-style signals in three steps
Paste, run, read. Nothing to configure first.
- Step 1
- Paste the text you're checking. A paragraph runs; a longer sample gives the check more rhythm to measure.
- Step 2
- Press Check text. It goes to our AI server once, gets scored for AI-writing patterns, and returns.
- Step 3
- Read each flagged signal and its reason, then decide for yourself what it means for the piece.
The honest limit
Can this predict what GPTZero will report?
No, and no outside tool can. GPTZero's exact scoring model, thresholds and training data are proprietary, and the company updates them without public notice. Any claim to reproduce its number would be a guess dressed up as precision.
What this tool can do honestly is look at the writing itself and report perplexity-and-burstiness-style patterns, a genuinely useful, separate signal from whatever GPTZero itself would return.
Why flags happen
Why honest writing still gets flagged
Low perplexity and low burstiness aren't unique to AI. Plenty of careful human writing shares the same flat, predictable rhythm for reasons that have nothing to do with a chatbot.
- Second-language writers
- Writing carefully in a non-native language tends to favor safe, predictable word choices, which reads as low perplexity.
- Neurodivergent writers
- Some writers naturally produce more even, formulaic sentence rhythm, which a burstiness check reads as machine-typical.
- Formulaic professional prose
- Technical manuals, compliance documents and form letters are written to be predictable on purpose.
- Heavily edited AI drafts
- Sentence-by-sentence human rewriting of an AI draft can raise both measures without the content becoming genuinely different.
If you're flagged
What to do if your writing is wrongly flagged
A flag from this tool, or any detector, is a signal, not a verdict. Institutions and employers set their own policy for what happens next.
- Keep your drafts
- Outlines and earlier versions are the plainest proof a piece grew, rather than appeared whole.
- Keep version history on
- Google Docs and Word log revisions automatically. Don't clear it while a question is open.
- Ask what was actually flagged
- A named pattern can be discussed. A bare score can't.
Who uses it
Who uses the AI GPTZero checker, and when
Anyone weighing whether a piece of writing will read as flat and machine-typical before it's reviewed.
- Students
- A private check before submission, alongside their own honest read of the draft.
- Editors
- Screening submissions for unusually even sentence rhythm before a full editorial pass.
- Hiring teams
- Checking whether a writing sample reads noticeably flatter than the rest of an application.
Free checks
How many free checks you get, and why
This check runs on our AI server, since the pattern model is too large for a browser tab. Each check is one round trip: text out, result back.
You get 5 free checks in any rolling 24 hours, tracked without an account. The window rolls forward from your last check rather than resetting at a fixed hour.