Is ZeroGPT a good AI detector?
A free web checker answers one question. Whether it answers it well depends on numbers most free tools do not put next to the result.
ZeroGPT is a free browser-based checker: paste text, get a percentage. That format is genuinely useful and it also hides the two things that decide whether the percentage is worth anything.
What "good" has to mean here
A detector makes two errors and they are not symmetrical. Missing generated text costs nobody anything that afternoon. Flagging something a person wrote arrives attached to their work.
An accuracy figure blends them. The number that describes your own exposure is the wrong-flag rate on human writing, and it is the one to look for on any tool's page.
Turnitin publishes 4%. Ours is 0.4%, which is 99.6% specificity, measured across 15,900 documents of real academic writing.
The two things a paste box does not tell you
How much text it scored. Length is the largest single factor in whether a result means anything. Turnitin's own figures show the size of it: 4% wrong on sentences against under 1% on documents, the same tool four times worse at the smaller unit.
Any cap that forces you to check an essay in pieces does not just inconvenience you, it degrades the answer, because you are asking for several unreliable small results instead of one reliable large one. See why detectors are unreliable on short text.
Where in the document the signal is. A single percentage over 2,000 words is an average. A 30% concentrated in one section and a 30% spread evenly are different findings, and the document figure cannot separate them. Per-paragraph output can.
What every free checker is reading
The same properties, whichever brand is on the page.
Predictable word choice. Formal, conventional prose is predictable prose.
Even sentence rhythm. Human academic writing in our corpus varies sentence length with a standard deviation of 8.7 words, generated text with 6.4.
Which means the same kinds of human writing score high everywhere: heavily edited work, technical and methods sections, and writing by non-native English speakers. See why AI detectors flag human writing.
Using free checkers well
- Run the whole document, never an extract, wherever the tool allows it
- Prefer per-passage output over a single document percentage
- Ask what the tool does with your text before pasting unpublished work. See
what happens to text you paste
- Run a second one and treat wide disagreement as the finding. See
Ours is free and unlimited with no account, takes .pdf, .docx and .tex, has no word cap, scores every paragraph separately, publishes its wrong-flag rate, and never stores your text.