About IsThisAiWritten

IsThisAiWritten is an independent, free AI detector. You paste text, it runs a detection model inside your browser, and you get a plain report. There is no account, no word limit and no upload.

Why it exists

Most AI checkers ask for an account, cap the length of what you can paste, or send your text to their servers. That is a poor fit for the people who need a quick answer most often: a student checking their own essay before handing it in, an editor with a 90,000-word manuscript, or someone who simply doesn't want a private document stored on a stranger's server.

We built the opposite. The detection model downloads once to your device and does its work there. Close the tab and nothing remains anywhere but your own browser cache.

How it is tested

The detector is tested on an open benchmark: a frozen set of human and AI texts, scored exactly the way your browser scores them. Its cut-offs are set per text length to keep false flags on human writing low, and the whole method is on the methodology page.

What we aim for is the most useful free check there is: no account, no limit on length, nothing uploaded, and a report that shows which passages and phrases drive the result.

What we won't do

• Show a percentage that pretends to be certainty. A result is an estimate, and we say how confident it is.
• Encourage anyone to punish a person on the strength of a detector score alone, ours or anyone else's.
• Collect your text. There is nothing to collect: it never leaves your device.

Who runs it

IsThisAiWritten is run by Luis, its founder, from Switzerland. How we write comparisons and articles, and how corrections work, is set out in our editorial policy. To reach us, write to [email protected] or use the contact page.

Research we build on

The narrative fingerprint for fiction draws on StoryScope (Russell et al., COLM 2026). The style explanations draw on published work on how language models write differently from people. The detection model is an open classifier released on Hugging Face under the MIT licence. We are not affiliated with any of these authors, nor with any company named on this site.