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GPTZeroUndetectable AI
Freemium

Free scans up to 10,000 characters, with paid upgrades for advanced features.

 Freemium

Free to use in the browser, with business plans offered.

Web, Browser extension Web, Browser extension
  • Sentence-level highlighting rather than a single score
  • Writing replay in Google Docs shows how a document was produced
  • AI text detection with sentence-level highlighting
  • Rewriter for stiff or machine-sounding text
  • AI detection is probabilistic and can misclassify human writing
  • Free scans are limited in length
  • AI detection results are estimates and can be wrong
  • Using the humanizer to pass off AI text may breach academic or workplace rules
Web application, Browser extension Web application, Browser extension
Closed source Closed source
License not stated License not stated
Not stated if an account is needed Not stated if an account is needed
Needs internet Needs internet

Checked September 26, 2026

Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.