What is the difference between ZeroGPT and GPTZero?
They are two unrelated products with almost the same name — GPTZero is the detector built by Edward Tian and marketed to institutions, while ZeroGPT is a separate free tool from a different operator, and the pair are confused constantly.
Last reviewed 15 August 2026 · The HumanFlow team
The name collision is the whole problem. Reversing two syllables produces the other company, so a student told their work was flagged by one has a decent chance of researching the other, and screenshots circulate attributed to the wrong tool routinely.
They differ in what they publish about themselves, which is the practical way to tell them apart. GPTZero has a named founder, published research positioning and an institutional product. ZeroGPT is a free web tool whose published documentation is thinner, and our page on it goes through what the site does and does not state.
If a score has been quoted at you, establishing which tool produced it is a reasonable first question and occasionally a decisive one. An institution using an unlicensed free web tool to support a misconduct allegation is a materially different situation from one using a product it has procured and configured.
Neither name tells you anything about accuracy. The similarity is a branding accident, and the two should be assessed separately on what each publishes.
When this answer changes
Products get renamed and acquired. If you are reading this some time after the review date, confirm the current owner of each before relying on the distinction.
Some institutions use neither and run detection inside their existing similarity platform, in which case the score came from a third product with a different name again.
Where to go next
- GPTZero, examined — What the tool publishes about its own accuracy.
- ZeroGPT, examined — What its own documentation states, and what it leaves unstated.
- How accurate detectors are — The independent testing, rather than either vendor's own figure.
Sources
One of our direct answers.