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Copyleaks API
Content-integrity API for AI detection and plagiarism scanning, billed in unified credits per scan.
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Listed API
GPTZero API
AI detection API exposing the same document, sentence and paragraph scores used by the GPTZero web app.
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Not tested yet
No detector-panel result exists for GPTZero API. Anything on this page about detectors below is the vendor's own claim, not a measurement. Ask us to test it, or run the procedure yourself.
The facts we hold
| Category | Humanizer APIs |
|---|---|
| Price model | Freemium Source: vendor page , read 2026-09-20 |
| Free allowance | Not stated |
| Works without an account | Yes |
| Developer API | Yes · docs |
| Browser extension | Not stated |
| Languages | Not stated |
| Vendor | GPTZero (US) |
| Added to the directory | 2026-09-20 |
"Not stated" means the vendor does not publish it, or publishes it somewhere we could not read at the source. It is not a judgement, and we do not fill the gap with an estimate.
No score yet, and here is why
A score on this site means a person used the tool, ran the fixed test texts through 6 detectors and published the numbers with a date. That has not happened for GPTZero API. What is above is what the vendor says about itself.
Vendors can ask for a review. Buyers can ask for one too - tell us which tool you need checked.
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