Free AI Text Detector — Check if Text Was Written by AI
Paste up to 2,000 characters. We run the same detector that powers Cereby's paid app and return a 0 to 100 score, a verdict, and the signals that drove it.
How to use this tool
Paste the text you want to check (between 50 and 2,000 characters).
Solve the quick verification challenge.
Click 'Scan for AI'. The detector runs on our server and returns in a few seconds.
Read the score, the verdict, and the signal breakdown.
When you'd use this
- Sanity-checking a draft before turning it in
- Spotting AI-written sections in a longer piece you're editing
- Validating that your humanized output now reads as human
- Quickly testing how a detector reacts to different rewrite styles
Why this tool exists
Modern AI text classifiers look for statistical fingerprints, not specific words. They learn that AI output tends to be smoother, more predictable, and structurally uniform compared to human writing, which is rougher and more varied. The score reflects how strongly your text matches the AI side of that distribution.
A few things to keep in mind. First, scores are not absolutes. A polished, formal piece by a careful human can score high; a lightly edited AI draft can score low. Second, signals are explanations, not proof. When the detector flags 'high em dash density', it means that pattern is common in AI output, not that em dashes are inherently AI. Third, classifiers update. What scored 90 last quarter might score 60 today as the detector and humanizers evolve in parallel.
The most useful workflow is iterative: detect, rewrite the highest-signal sections, detect again, see what moved. The free tool gives you the detect side of that loop. The full Cereby app pairs it with a rule-based humanizer, per-paragraph scores, and detector feedback that tells the humanizer which signals to attack on the next pass.