ZeroGPT AI Detector: Review & Free Check
Paste any text below for a free AI score, no account needed. This is Humanit's checker, not ZeroGPT. Under it: how ZeroGPT scores text, why it is not the same thing as GPTZero, and how much its percentage deserves.
ZeroGPT is a free AI detector that checks up to 15,000 characters at a time, highlights the sentences it thinks are AI-written and shows an overall AI percentage. It is a different company from GPTZero, and its accuracy claims are its own, with no external study cited on its page.
Works with every major AI model
How it works
- 1Paste your text. Drop in the writing you want to check against ZeroGPT-style detection.
- 2Run the free detector. Humanit returns a 0–100 AI-likelihood score, a verdict, and the signals behind it.
- 3See what reads as AI. The subscores show which patterns — predictable phrasing, uniform rhythm, stock vocabulary — are pulling the score up.
- 4Fix it if needed. If it reads as AI, send it to the humanizer to rewrite those signals, then re-check.
ZeroGPT is not GPTZero
The names cause endless confusion, so first things first: ZeroGPT (zerogpt.com) and GPTZero (gptzero.me) are different products from different companies. GPTZero was bought by Superhuman, the company behind Grammarly, in June 2026; ZeroGPT is unrelated. They score text differently, label results differently, and will often disagree about the same paragraph. If a teacher says a detector flagged your work, the first question is which one. The GPTZero AI detector page covers the other one, and the GPTZero vs ZeroGPT comparison puts them side by side.
What ZeroGPT checks and what it shows you
ZeroGPT's free checker takes up to 15,000 characters per check — roughly 2,500 words — which is one of the larger free limits among popular detectors. It returns a gauge showing the percentage of AI in the text and highlights every sentence it attributes to AI. ZeroGPT calls its method DeepAnalyse technology and says it covers more than 20 families of language models. Around the detector it has built a large toolbox — humanizer, paraphraser, summarizer, grammar checker, translator, plagiarism checker, image and video detectors — plus an API and batch file uploads for heavier users.
How accurate is ZeroGPT?
ZeroGPT advertises very high detection accuracy and a false-positive rate below one percent. Those are its own figures: the page cites no external study, and a vendor's accuracy is always measured on the vendor's chosen test set. Public demonstrations point the other way at the edges — one widely shared test had ZeroGPT rating the Declaration of Independence as almost entirely AI-written, because formal, evenly-paced prose looks statistically machine-like. The deeper look at its claims, false positives, and why detectors disagree is in is ZeroGPT accurate?.
Why ZeroGPT flags human writing
Every statistical detector, ZeroGPT included, rewards irregularity: varied sentence lengths, specific details, a personal voice. Writing that is clean, formal, formulaic or composed in a second language has less of that, and it is flagged more often — a 2023 peer-reviewed study in Patterns found more than 61% of genuine TOEFL essays by non-native English speakers were misclassified as AI by the detectors it tested. Sentence-level highlights are the least stable part of any detector's output; a single highlighted sentence in otherwise human text means very little.
What to do with a ZeroGPT score
Read it as a temperature, not a verdict. A high score on a long, unedited passage is a real signal; a mid-range score says little on its own; and a score from one detector tells you nothing about what a different detector — such as the Turnitin your school may run — will say. If your own writing is flagged, vary sentence length, cut stock transitions and add specifics, then re-check. If the draft is AI-assisted and that is allowed for your task, restructure it properly rather than swapping synonyms, and verify the result.
A second opinion, with the reasoning shown
Humanit's detector above is free with no account for up to 300 words per check — smaller than ZeroGPT's free limit, to be straight about it. What it adds is the reasoning: a 0–100 score split into sub-signals like perplexity, burstiness, AI vocabulary and structure, plus the exact phrases pulling the score up, and a humanizer on the same page if a passage needs rework.
Who it's for
| Feature | ZeroGPT | Humanit detector |
|---|---|---|
| Free check size | Up to 15,000 characters | Yes, up to 300 words per check |
| What you see | AI percentage gauge + highlighted sentences | 0–100 score + sub-signals + flagged phrases |
| Accuracy claim | Very high, own figures, no study cited | An estimate; we publish no accuracy figure |
| Batch uploads and API | Yes | No |
| Rewrite flagged text in place | Separate humanizer tool | Yes, humanizer on the same page |
Frequently asked questions
Is this the official ZeroGPT detector?
No. This is Humanit's free detector, useful as a second opinion. ZeroGPT's own checker is at zerogpt.com.
Is ZeroGPT the same as GPTZero?
No. They are separate products from separate companies. GPTZero is owned by Superhuman, the company behind Grammarly, since June 2026; ZeroGPT is unrelated, and the two often score the same text differently.
Is ZeroGPT accurate?
ZeroGPT advertises very high accuracy and a false-positive rate under one percent, but cites no external study for those figures. Like every detector it is most reliable on long, raw AI text and least reliable on edited, formal or non-native English writing.
Is ZeroGPT free?
Yes, the web checker is free for up to 15,000 characters per check, with paid plans for heavier use, batch uploads and API access.
Which is better, GPTZero or ZeroGPT?
Neither is independently proven better. GPTZero labels results (Human, AI + Human, Polished by AI and more) and gives a probability for the whole document; ZeroGPT highlights sentences and shows an AI percentage. Running both and seeing whether they agree is more informative than trusting either alone.
Why did ZeroGPT flag my own writing?
Formal, evenly-paced or formulaic writing looks statistically similar to AI text, and non-native English writing is flagged most often. Varying sentence length and adding specific detail usually lowers the score.
Will my text be used to train AI?
No. Your text is sent to the model only to produce your result and is never used to train any AI. No content is stored beyond the request.
Does it keep my original meaning?
Yes. Humanit preserves your facts, numbers, names, and citations while changing the phrasing and structure. It never invents new claims.