AI Content Detector

A free AI content detector that shows its working

Most free AI checkers give you a single percentage and nothing else. You cannot see why the number is high, so you cannot judge whether to trust it. This one tells you which writing signals pushed the score up or down, highlights the sentences that carry stock AI patterns, and says plainly when the evidence is mixed.

It is built for editors checking freelance work, teachers who want a second opinion before a conversation, SEO teams reviewing drafts before they publish, and writers who want their own work to read less like a machine. It is free, needs no signup, and does not store what you paste.

A note on honesty. Until September 2026 this page ran an older method. When we tested it properly, it scored almost every text around 30 percent, whoever wrote it, so it could not tell people from AI at all. We threw it out and rebuilt the detector around signals that held up on text they had never seen. The results of that test are below.

What the detector looks at

It does not run a large language model. Paid detectors such as GPTZero and Grammarly train machine learning models on large collections of human and AI writing, which is how they reach higher accuracy. This tool is a transparent statistical check that runs in milliseconds, and it is upfront about where that stops.

How accurate is it? Our own test

In September 2026 we ran the detector on 57 texts. The 30 human samples were all written before modern AI chatbots existed: Wikipedia articles from 2019, Hacker News comments from 2015 and Stack Exchange answers from 2010 to 2016. The 27 AI samples covered essays, emails, product copy, stories, listicles, technical explainers and blog posts. We tuned the tool on 23 of them and then checked it on 34 it had never seen.

Whenever it gave a clear verdict, it was right. It declined to decide on 23 of the 57 texts, and that is deliberate: a wrong accusation does more harm than an honest shrug.

Read these numbers with care. The test was small, and every AI sample came from one model family, so text from other models and AI drafts that a person has edited will land in the unclear band more often. Your results will vary with the kind of writing you check.

Why no AI detector is proof

In 2023, researchers at Stanford tested seven popular AI detectors on essays written by people. The detectors flagged 61 percent of TOEFL essays by non native English speakers as AI, and 89 of the 91 essays were flagged by at least one detector. Essays by native speakers were judged almost perfectly. Read the Stanford summary.

The reason is simple. Careful, formal and second language writing shares traits with AI text: clean grammar, even sentences, few informal marks. Edited AI text blurs the other way. Even Grammarly describes its own detector as a starting point for review, not final proof.

This tool builds that caution in:

• A wide unclear band from 35 to 69, where it draws no conclusion.
• Texts under 150 words need a score of 75, not 70, before it says AI.
• It refuses to check fewer than 80 words.
• Reliability is shown as Low or Moderate. It never claims High.

How to use the result well

If you are checking someone else's work

Use a high score as a reason to talk, not a verdict. Ask about the process, look at earlier drafts or version history, and compare with writing you know is theirs. An unclear result means the tool cannot tell, not that someone is hiding something.

If you are checking your own writing

Open the highlighted sentences and the writing tips. Cut stock openers, swap AI favourite words for plainer ones, vary your sentence length, and add something only you know: a number from your own work, a quote, a short aside. Those edits make writing better for readers, which matters more than any score.

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Frequently asked questions