Was this AI-written?
Paste prose or upload a document. We estimate the probability it was written by an LLM, with the tells. It’s a confidence signal — not proof — and it reads writing style, not whether a document is genuine.
AI likelihood
—%
Run a check to see the readout — a probability, the lean, and the tells behind it.
About the AI text detector
The AI text detector estimates how likely a passage of prose was written by a large language model rather than a person. Paste text, or upload a PDF, .txt, or .md file, and it returns a probability with the specific stylistic tells behind the score — repetitive hedging, uniform sentence rhythm, generic transitions, and the like.
It reads writing style, not document authenticity. A genuine PDF can be AI-written and a forged one can be hand-typed, so this is the wrong tool for spotting a doctored payslip or a fake invoice. For that, use the document verifier.
- 01
Paste prose or upload a file
Send at least a paragraph of running text, or a PDF / .txt / .md document — the detector pulls the prose out of it.
- 02
It confirms the text is actually prose
Forms, tables, and scanned layouts aren’t writing-style questions, so the detector abstains on them instead of guessing.
- 03
The prose is weighed for AI tells
A language model scores the passage and surfaces the concrete signals — phrasing, structure, and rhythm — that drove the estimate.
- 04
You get a probability and the tells
A 0–100% likelihood, a lean (AI, human, or inconclusive), and the reasoning, so you can judge the call rather than just take a number.
What you get back
AI-written probability
The model’s confidence, 0–100%, that the prose was generated by an LLM.
Lean + reasoning
A plain-language verdict — likely AI, likely human, or inconclusive — with the why.
The tells
The specific stylistic markers that pushed the score up or down.
Abstention
On non-prose (a form, table, or scan) it returns “not applicable” rather than a misleading score.
Common uses
- Triaging essays, applications, or support tickets for AI-written submissions
- Spot-checking research notes or reports before you rely on them
- Flagging prose for human review rather than auto-rejecting it
- Teaching and editorial workflows where authorship matters
AI-writing detection reads style, and style can mislead: careful human editing can lower a score, and non-native or formulaic writing can raise one. Use it as a signal to prompt review, not as an automated gatekeeper.
Questions
- Is the result proof that text was written by AI?
- No. It is a confidence signal, not proof. AI-writing detection is probabilistic — treat a high score as a prompt to look closer, never as a verdict on its own.
- Does a high score mean the text is bad or dishonest?
- No. AI-written does not mean wrong. Plenty of legitimate text is drafted or polished with an LLM. The detector reports how the text reads, not whether using AI was appropriate.
- Why did it refuse to score my document?
- It only assesses prose. If you upload a form, a table, or a scanned layout it abstains — authenticity there is a forensic question, so use the document verifier instead.
- How much text does it need?
- At least a paragraph. Very short snippets do not carry enough stylistic signal for a meaningful estimate.
- Do you store what I submit?
- No. The detector is stateless — your text or file is assessed and not retained.