ZeroClaude
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Free AI checker for essays

Paste your essay or upload a .docx or .pdf, and see which sentences read like AI before you submit.

0/15,000 Characters

Check your essay before you hand it in

See which sentences stand out

Every sentence that reads like AI is highlighted, so you know exactly what to rewrite.

Built to avoid false alarms

Thresholds are set on human writing, separately for English and Chinese, to keep false positives low.

Upload the file

Upload a .docx, .pdf or .txt file instead of copying and pasting.

Your essay is not stored

We keep scores only, never your text.

How to read the result

The percentage is the share of your essay that reads like AI, weighted by sentence length. A low score with one or two highlighted sentences usually means a few phrases sound generic; a high score across the whole essay means most of it reads like AI output. Scores are probabilistic estimates, not proof either way.

If you used AI to brainstorm or outline, write the essay itself in your own words, and check that your school's rules allow the help you used.

FAQ

Your questions, answered

Is it free?
Yes. You can check up to 15,000 characters at a time without an account. Paid plans raise the limit and add PDF reports and batch upload.
How long should the text be?
At least 150 words. Scores on short passages are less reliable, so check a whole essay or a full section rather than a single paragraph.
My own writing was flagged. What should I do?
Formal, polished writing can look AI-like. Rewrite flagged sentences in your own voice, add specific details only you would know, and keep your drafts and notes as a record of your work.
Will my teacher's checker give the same score?
Not necessarily. Each checker uses its own model and thresholds, so the same essay can score differently across them. Use ZeroClaude to find passages that read like AI and revise them before you submit.
Which languages does it work in?
Detection is trained and calibrated for English and Chinese. Text in other languages can be checked, but the result is marked as experimental until we have checked that language for false positives.
Do you keep my text?
No. Your text is only used to produce the result and is never written to a database. If you are logged in, your history keeps the score and date, not the text.
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