AI Detector for Essays
Updated
This AI detector for essays checks a full essay of 300 words or more and returns a probability that it was AI-generated, with the flagged sentences highlighted. Students use it to check their own drafts before submitting; teachers use it as one signal among several, never as proof on its own.
Limitations: Every result is a probability that can be wrong, not proof of how something was written. How results can be wrong →
3 free scans in total, shared across all five tools (not per day or per month). No signup needed to start.
How the AI Detector for Essays Works
- Paste or upload: paste the essay, or upload a .txt, .md, .docx or .pdf file up to 8 MB.
- Length: essays need at least 300 words; the maximum is 150,000 characters, longer than almost any essay.
- Result: a probability score, a plain-language verdict and the sentences that pushed the score up.
- Language: the site supports English only.
Why Essays Are Hard to Judge
Academic essays follow a predictable structure: a thesis, topic sentences, formal transitions and a summary conclusion. That same predictability is what many AI detectors look for, so a careful, formulaic human essay can score higher than a messy one.
Essays that were drafted with AI and then heavily rewritten, or written by a person and then polished with a grammar tool, sit in a grey area. A detector cannot tell you which of these happened, only how the final text reads.
Checking Your Own Essay
If you wrote the essay yourself and it scores high, look at the highlighted sentences. They are often the most generic ones: broad openings, stock transitions and summaries that repeat the question. Rewriting those in your own voice usually makes the essay better, whatever the score.
Keep your drafts, notes and version history. If your work is ever questioned, the writing process is much stronger evidence than any detector result.
For Teachers Reviewing Essays
Treat a high score as a reason to talk to the student, not as a finding. Compare the essay with their earlier work, ask them to explain their argument, and check their draft history if your platform keeps one.
Detectors are known to flag human writing, including work by non-native English writers, so a score should never decide a grade or a misconduct case by itself.
Frequently asked questions
At least 300 words. Shorter texts don't give the detector enough to work with, so the check won't run.
Yes. Upload a .docx, .pdf, .txt or .md file up to 8 MB, and the text is extracted for the check.
No. The score is a probability and can be wrong, especially for formal or formulaic writing. Use it alongside drafts, conversation and the student's earlier work.
If you are signed in, scan history keeps the first 200 characters of the text. The text is also sent to the detection provider listed on the How It Works page.
Sources
- GPT detectors are biased against non-native English writers (Liang, Yuksekgonul, Mao, Wu, Zou) (arXiv 2304.02819, read on )