AI Free Single HTML file

AI Writing Detector

AI Writing Detector is a free browser tool that checks whether English prose reads like AI, using nine offline heuristics on up to 5,000 words — your text never uploads.

AI Writing Detector is a free, single-file browser tool that checks whether English prose reads like AI — using nine offline heuristics across cliché phrases, sentence-length uniformity, em-dash patterns, discourse markers, and more. Up to 5,000 words. Your text never leaves your computer. Built by Nirav Bhatt at Brain Bound Learning.

This Single Page Sandbox tool was originally published on: Brain Bound Learning Substack

Get the tool

Runs in your browserNo accountNo uploadNo install

Free with a newsletter subscription

The download is one self-contained HTML file. Open it from your desktop and it works with no internet connection. Terms of Use.

Silent screen recording of AI Writing Detector: a short conversational passage is pasted in and verified — it scores 0% and every signal row stays green — then an AI-styled passage is pasted and verified, and the cliché-phrase, discourse-marker and em-dash rows turn red. Every step is written out in About AI Writing Detector below.

A free, private AI writing detector that runs in your browser

AI Writing Detector is a free, private tool that checks whether English prose reads like AI, using nine offline heuristics — cliche phrases, sentence-length uniformity, em-dash patterns, discourse markers and more — for up to 5,000 words. It flags patterns; it does not prove authorship. Your text never leaves your browser.

How it works

  1. Paste up to 5,000 words of English prose into the box. Past the limit the word counter turns red and the verify button disables.
  2. Press Verify AI. The whole analysis runs in the page — nothing is sent anywhere.
  3. Read the overall AI-likelihood score, 0–100%, and its verdict band: likely human, mixed signals, probably AI-assisted, or very likely AI.
  4. Work down the nine-signal breakdown. Each row shows its own score, its red-flag threshold, and the sentence from your text that best illustrates it.

What you can use it for

Frequently asked questions

Is it accurate?

It reports heuristic signals, not proof. It flags patterns common in AI-generated prose; it does not prove who or what wrote a passage. Use it as one input, not a verdict.

Does my text get uploaded?

No. Analysis runs entirely in your browser and your text never leaves your computer.

Is it free?

Yes — free, with no account and no API key.

What can it check?

English prose, up to 5,000 words at a time.

See the full FAQ for all Single Page Sandbox tools →