An AI detector for essays, with a sentence-by-sentence map

Paste an essay below and this AI detector for essays gives you an outcome and a sentence-by-sentence map, free and without an account. There is no word limit, and the essay is checked in your browser, never uploaded.

What a result can't tell you about an essay

Like any detector, it can be wrong in both directions, so treat a result as a reason to look closer, not as proof. Our methodology page explains how it is tested.

Some human essays are easier for detectors to mistake for AI than others. Research on detectors has found that plain English, such as essays by students writing in a second language or taught to keep sentences short and simple, is flagged more often. Formulaic structure adds risk too. A five-paragraph essay that opens with a dictionary definition and closes on “In conclusion” is formulaic in exactly the way detectors can mistake for AI. Our post on AI detectors and non-native English looks at this in more depth.

Preparing an essay for an AI check

A couple of minutes of preparation makes the result easier to read:

• Remove the title page, the reference list and any appendices. They aren't the essay's own prose, and a bibliography is formulaic by nature.
• Take out long block quotations from sources, so the writer's own sentences are what gets scored.
• Check that the essay is in English. Other languages get Inconclusive rather than a guess.
• Make sure at least 150 words of body text remain. Under 150 words confidence is always low, and under 50 there is no result.

How to check an essay for AI

1. Paste the prepared essay into the box above, or open the .docx file directly.
2. Press Check for AI.
3. Read the outcome with its confidence word, and the reason given for it.
4. Look at the AI-likeness line, which reads “more AI-like than X% of human writing we tested”.
5. Open the sentence map and read the highest-scoring passages in context. They are high compared with the rest of this essay, which is a reason to look, nothing more.

Reading Mixed, AI and Inconclusive on an essay

Mixed means at least one substantial passage, around 120 words or more, scored as AI while the rest didn't. On an essay that sometimes lines up with a pasted-in paragraph, and sometimes just with the most formal section, such as a summary of the literature. AI means most of the text scored as AI and the overall score cleared the AI cut-off. Inconclusive comes with a reason: too short, not English, or evidence that pointed both ways. Treat it as no answer at all.

Using an AI detector for essays fairly

If you're a student checking your own work, a flag tells you how your essay reads to one statistical model. Your drafts and version history are a far better record of how you wrote it, so keep them. The students page covers what to do next.

If you're marking, a result is a reason to talk with the student, alongside their drafts and how well they can discuss the material. It should never be the only evidence against anyone. The teachers page has a workflow for that conversation, and our post on being wrongly flagged covers the other side of it.

A careful reader will also catch things no detector can, such as an essay that doesn't answer the question that was set.