AI Detector & Plagiarism Checker
Paste any text to see which parts ChatGPT, Claude, Gemini or another AI wrote, and check it for plagiarism.
Free: the first 300 words, 3 checks a day. No sign-up.
How it works
- Paste your text. Essays, articles, emails, cover letters: anything over 40 words.
- See what AI wrote. Each passage is marked AI-generated, AI-assisted or human-written.
- Check for plagiarism. Plus finds copied passages online and shows you the sources.
Highlights, not just a score
See exactly which passages read as AI-generated, AI-assisted or human.
Spots edited AI text
Flags AI text that was paraphrased or run through a “humanizer”.
Plagiarism with sources
Matches against the web, with the share of sentences copied and links to each source.
Private by default
Your text is never used to train models. Free checks are deleted after a day, paid ones after 30 days.
Unlock AI Checker Plus
Full-length checks up to 5,000 words, plagiarism with sources, highlights, shareable reports and history. 20,000 words a month on every plan.
Secure checkout by Stripe. Cancel anytime. Refund within 7 days if you've used under 2,000 words.
Questions
How accurate is it?
It uses a detection model trained on millions of human and AI-written documents and is built to keep false alarms rare. Still, no detector is perfect: treat the result as strong evidence, not proof, and look at the highlighted passages.
Can a result prove someone cheated?
No. A detector gives a probability. Before acting on it, talk to the writer, look at drafts and version history, and use the highlights to ask specific questions.
Which AI models does it detect?
Text from ChatGPT (GPT-4o, GPT-5 and others), Claude, Gemini, Llama, DeepSeek, Grok and other popular models, including AI text that was edited or paraphrased.
What does the free check include?
An AI check of the first 300 words, 3 times a day, with highlights. Plus checks up to 5,000 words at once and adds plagiarism checks, shareable reports and history.
Do you store my text?
Only so you can see your result: free checks are deleted after a day and paid checks after 30 days. We never sell your text or use it to train AI.
Can I cancel or get a refund?
Monthly and yearly plans cancel anytime from your account page (you keep access to the end of the period). The semester pass doesn't renew. If it isn't for you, ask for a refund within 7 days if you've used under 2,000 words.