Detectors

The detector most students meet. It reports a percentage of a submission that it judges likely AI-written. AI bypasser detection, announced August 27, 2025, flags text that humanizer tools may have rewritten and counts it toward the AI-generated total. Bypasser detection is trained and tested for English only.

Several universities have switched the AI indicator off over false-positive concerns. Turnitin's own guide says a score should start a conversation, not decide an outcome.

Turnitin's own description of how the model is trained, what the percentage means, which languages are covered and where it says the score should not be used alone.

A trained classifier that explicitly targets humanized text as well as raw model output. Pangram publishes its own comparisons and reports detection above 90 percent on high-quality humanized content.

Those figures are vendor-reported. No independent study of the same claim had been published when this entry was checked.

Education-focused detector with per-sentence highlighting, document reports and a writing-replay feature for Google Docs that shows how a draft was typed.

Built for publishers, agencies and SEO teams. Combines AI detection with plagiarism, readability and fact-check tools, and publishes its own benchmark studies.

Enterprise and education detector that also covers source-code and plagiarism checks. Claims low false-positive rates in its own testing.

A free checker from the academic editing service, with a premium tier for longer documents.

Highlights sentences by estimated likelihood and ships as a browser extension.

One of the most-visited free checkers.

Independent tests often report inconsistent scores on the same text, so treat it as a rough signal.

A quick check from the enterprise writing platform, limited to short samples.

A zero-shot method that compares how two related models score the same text, with no detector training data. Useful as an independent baseline when you do not trust a vendor's number.