Paste
Use drafts, replies, or page copy.
AI text checker
AI text checker with clear reasons
Paste writing and get AI probability, human score, generic-writing score, key reasons, and highlights.
Result
Waiting
Run a check to see AI probability, confidence, key reasons, and next steps.
Preview
%
AI probability
AI vs human estimate
Human-like cues
Human-like context
Calibration
Confidence and next steps
Context only. Scores can help you review text, but they do not prove authorship or origin.
AI probability is an estimate to help you review content. It is not proof that someone did or did not use AI.
Check
The checker looks for measurable writing patterns.
Review
Use the score to ask for context or edits.
Questions
How much text should I paste?+
Aim for at least 80 words when possible. Short samples can run with lower confidence.
Can this prove AI authorship?+
No. AI Checker Lab returns probability estimates to help you review content. It should not be used as proof or an accusation.
Does AI Checker Lab save my checks?+
Anonymous checks are not saved to an account. Signed-in users can save recent check history with a short preview, scores, and result details so they can review past results.
Why can AI checkers disagree?+
AI detection is uncertain. Different tools weigh style, length, topic, and evidence differently, so context matters.