AI Writing Detector
A heuristic detector for AI-generated English prose. Paste up to 5,000 words, hit Verify, and get a weighted AI-likelihood score (0–100%) with a per-signal breakdown.
AI Writing Detector — a free, private GPTZero alternative
AI Writing Detector is a free, private alternative to online AI detectors like GPTZero, ZeroGPT and Originality.ai. It 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.
What you can use it for
- Editors screening submissions before publishing
- Writers self-checking that a draft doesn't read like AI
- Bloggers and content reviewers doing a quick sanity pass
- Anyone wary of pasting private text into an online detector
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.