Free AI-text estimate

Was this text likely written by AI?

Paste at least 50 words of English. A statistical model gives an estimate - not proof - and shows the words that pushed it either way. It runs in your browser: your text is never sent to us.

Your text

Paste an English passage of 50 words or more: an essay, an abstract, a paragraph. The text stays in your browser; nothing is uploaded or stored.

Estimate

Scores the text from 0 (reads like human writing) to 100 (reads like AI writing), and lists the words that pushed the score each way. It is a statistical estimate with known error rates, shown below - never proof of who wrote a text.
What this estimate can and cannot tell you
Tested onAI caughtHuman wrongly flagged
Texts like its training data99%1.7%
A topic it never saw (finance)97.5%2.2%
Fiction6.6%0%
Text from an AI model family it never saw39%3%
Independent benchmark: 11 AI models, 8 kinds of text33%3%
Research abstracts in that benchmark37%7%

So: when it says AI on familiar kinds of text, it is usually right; when it says human, that proves little, because it misses most text from newer or unfamiliar AI models. On research abstracts it wrongly flags about 7 in 100 human-written ones.

Never use this score alone to accuse a student or an author. It is untested on non-English text, on heavily edited AI text and on the newest AI models.

A free tool, separate from our rewriting service. Trained on the public HC3 (Guo et al., CC BY-SA 4.0) and Ghostbuster (Verma et al., 2023) datasets.

How we think about academic integrity