AI Detector
AI Detector — gauge how human your text reads.
Estimate how likely a passage is AI-generated, with sentence-level highlighting. A signal to investigate — never a verdict.
Text to analyze
Awaiting text
Paste text and press Analyze
Sentence breakdown
Sentences likely to be AI-written are highlighted here after analysis.
AI detection is probabilistic, not definitive — never use it as sole proof.
How the AI detector works
1
Paste your text
Add the passage you want to evaluate.
2
Analyze
Phrasera estimates an overall AI-likelihood and scores each sentence.
3
Investigate
Use highlights as a starting point — then verify with judgment.
More writing tools
One toolkit instead of ten tabs — every Phrasera tool is free to try, no signup required.
Paraphraser
Rewrite anything, any style
Open Paraphraser →Grammar Checker
Fix grammar & spelling
Open Grammar Checker →Summarizer
Condense to the essentials
Open Summarizer →Plagiarism Checker
Scan for matched sources
Open Plagiarism Checker →Citation Generator
APA, MLA, Chicago & more
Open Citation Generator →Translator
Natural, fluent translation
Open Translator →Word Counter
Words, characters, reading time
Open Word Counter →AI Humanizer
Make AI text sound human
Open AI Humanizer →AI Detector FAQ
AI detection is probabilistic, not definitive — the score is an estimate, not proof. Both AI and human writing can be misclassified, so never use a detector as the sole basis for a decision.
The percentage is the model's estimated likelihood that the text was AI-generated. Higher means more AI-like patterns were detected; it is not a guarantee.
Yes — you can analyze text for free without an account. Premium adds longer documents and higher daily limits.
No — you should never accuse or penalize anyone based solely on an AI detector. Treat the result as one weak signal among many, and talk to the writer.