ChatGPT Checker
Paste any text and find out in seconds whether it reads as ChatGPT — including GPT-5 and GPT-4o. Sentence-level highlighting shows exactly which lines drive the score, so you know what was flagged and why, not just a percentage.
500 words per check with no account — 1,000 words with a free one.
How it works
Paste the text
Drop in the essay, article, email, or post you want to check. Up to 500 words per check with no account; a free account raises that to 1,000 words with daily checks.
Get the ChatGPT score
You get an overall AI probability, a per-sentence breakdown showing exactly which lines read as ChatGPT, the signals that fired, and a confidence band for the result.
Check for watermarks too
ChatGPT output can carry invisible statistical watermarks. Run the companion watermark checker on the same text for an independent second signal beyond style analysis.
What gives ChatGPT away
ChatGPT has a recognizable statistical fingerprint, and the checker scores your text against it rather than guessing from vibes:
- Too-predictable word choices. ChatGPT picks high-probability words far more consistently than human writers do — that uniformity (low perplexity) is measurable sentence by sentence.
- Even, list-heavy structure. Uniform sentence lengths, tidy paragraph rhythms, and formulaic transitions like “moreover” and “it’s worth noting” are classic ChatGPT patterns.
- Invisible watermarks. OpenAI embeds statistical signatures in ChatGPT output. Style analysis and the watermark checker give you two independent signals on the same text.
The honest caveat: every ChatGPT detector — this one included — returns probabilities, not proof. Polished human writing sometimes looks statistically AI-like, so mid-range scores explicitly say “recommend human review” instead of pretending to certainty.