Free AI Detector
An AI detector checks whether text was written by an AI model. Paste your text below to get an AI probability score and see the exact sentences flagged as AI-written — then humanize them for free. No signup, instant results.
Paste text to check
0 / 1,500 wordsAfter you detect AI, humanize it
Flagged sentences are the ones to fix first. Run them through the free AI humanizer to rewrite AI text into natural human writing, then re-scan. These guides go deeper:
Frequently asked questions
What is an AI detector?
An AI detector is a tool that estimates whether a piece of text was written by an AI model. It analyzes patterns like word predictability (perplexity) and sentence-length variation (burstiness), then returns a probability and flags the specific sentences that read as machine-written.
How accurate is the AI detector?
It returns a probability and a confidence level rather than a yes/no verdict. No detector is 100% accurate — AI and human writing overlap — so treat the score as a strong signal to review the flagged sentences, not as absolute proof.
Is the AI detector free?
Yes. You can check text for free with no signup and no login. Paste up to 1,500 words per scan and get instant results.
What do the highlighted sentences mean?
Each highlighted sentence is one the detector flagged as AI-written. Rewrite or humanize those sentences first — they are the parts most likely to trip an AI detector.