A free AI detector for teachers, with no class limits

IsThisAiWritten is a free AI detector for teachers that checks student work inside your own browser: no account, no per-class limits, and no essay uploaded to anyone. Paste a submission below to see which passages to read first and what to ask, then let the conversation with the student, and the student's own evidence, do the rest.

Why teachers use it

• Free, with no sign-up. No account, no email and no credit card. No credits, no daily cap, no class-size limit, no paywall and no premium tier, so a full class set costs nothing.
• No word or character limit. A paragraph answer, a coursework essay or a whole dissertation goes in as one check.
• Nothing is uploaded. The check runs in your browser, so student work never leaves your device.
• Student work is never stored, shared, sold or used to train anything. We never receive it.
• Every word is scanned, never a sample.
• A report that explains itself: an AI-likeness score, sentence-by-sentence highlights, style notes with one-click plainer wording, and a hidden-character and look-alike-letter cleaner.
• Opens .txt and .docx files right in the browser, so submitted Word files need no copying.
• No ads where you paste text.

What an AI detector for teachers shows you

Every check gives you an outcome (Human, Mixed, AI or Inconclusive) with a confidence word, the AI-likeness line, and a sentence map that shades each sentence relative to the rest of the essay. That last part is what makes the result usable in a classroom: instead of a single number, you get specific passages to read and, if needed, to discuss with the student. Our methodology page explains how the detector is tested.

A workflow for checking a submission

1. Remove the cover sheet, bibliography and long quotations, and paste the student's own prose into the box above, or open the .docx file.
2. Press Check for AI.
3. Note the outcome, the confidence word and the AI-likeness line. If your school wants a record, download the result as JSON or print it to PDF.
4. If the outcome is AI or Mixed, read the passages the sentence map marks highest, in context, before deciding anything.
5. Compare with what you already know: the student's in-class writing, earlier drafts and the brief they were given.
6. If you still have concerns, talk with the student before reaching any conclusion.

What to do with an “AI” result

Treat it as a question to put to the student. Tell them you used a detector, show them the report and give them a real chance to respond. Ask for drafts, notes and the document's version history; many writing tools keep one automatically. Ask them to talk you through one argument in the essay, or to extend it by a paragraph while you wait. A student who wrote the work can usually do this without much trouble. The highlighted passages give you a concrete place to start, which keeps the conversation focused and short.

What to do with “Mixed” or “Inconclusive”

Mixed points you at one stretch of the essay, around 120 words or more, so read that passage before anything else. It might be a pasted-in paragraph, or simply the most formal writing in the piece, such as a summary of the set reading. Ask the student how that section came together.

Inconclusive means the evidence pointed both ways, and the detector says so, with its reason, rather than forcing a verdict. Move on to your own reading of the work.

Checking a whole class set

There is no daily cap, so you can go through a full set of essays in one sitting, one at a time. If you want to come back to earlier results, switch on Save scans on this device in the scan workspace. It is off by default, and the history is kept in your own browser's storage, never on a server. Each report can also be printed, saved as a PDF or copied as a short summary for your marking notes.

Why local checking helps with student privacy

Many schools limit which outside services can receive student work. Because this detector runs in the browser, the essay isn't sent anywhere or added to a database, and there is no account linking checks to you or your students. Anyone at your school can confirm this using the steps on the private AI detector page. The signs of AI writing post covers what to look for alongside the report, and AI detectors and non-native English is useful background if you teach students writing in an additional language.