Instant originality check

Spot AI-like writing
in secondsno login.

Paste plain text or LaTeX and get a calibrated AI-likelihood score with signal breakdown and sentence heatmap. Runs entirely in your browser — nothing is uploaded.

No account · no upload · works offline after load · LaTeX-aware
Live preview62% AI-like
62%AI-LIKE

Likely AI-assisted

Stock phrasing + low burstiness pulled the score up. Confidence 71%.

Furthermore, a robust framework for data collection is essential. Moreover, researchers must delve into the multifaceted nature…

Burstiness
Phrasing
Surprisal
Strict mode · higher sensitivity
9 signals · one calibrated score
No login requiredClient-side — text never leaves your deviceLaTeX stripped before scoring~60+ words for a usable estimate
How it works

Paste text. Get a score. Improve the draft.

Built for researchers who want a fast originality / AI-plagiarism check before submitting — without creating an account or uploading a manuscript.

01

Paste anything

Plain prose or LaTeX. Math, commands, and verbatim blocks are stripped so only the writing is scored.

02

Nine-signal ensemble

Surprisal, burstiness, lexical diversity, n-grams, function words, openers, punctuation, stock phrases, and contractions.

03

See what flagged

Gauge + per-signal bars + sentence heatmap. Hover any sentence for its local AI-like score.

What we measure

Signals that separate generic AI cadence from human rhythm.

Perplexity proxy
Surprisal from word frequency

Low, flat surprisal across tokens often reads as AI. We use a bundled Zipf frequency model — a proxy, not a full language model.

Rhythm
Burstiness & punctuation

Humans vary sentence length; many models don’t. Uniform commas and sparse questions or dashes also nudge the score.

Lexicon
Stock AI phrases & openers

“It is important to note,” “delve into,” “multifaceted,” repeated transition openers — classic tells we weight explicitly.

Stylometry
Function words, MATTR, contractions

Grammar-word share, moving-average type-token ratio, and contraction rate help catch formal, over-smoothed prose.

Be careful

A useful estimate — not a verdict.

Formal human academic writing can score high. Lightly edited AI can score low. No detector, including paid ones, can prove authorship. Use this to revise your own writing — never to accuse someone.

Check a passage in under a minute.

Free, no signup, nothing uploaded. Paste ~60+ words for a reliable estimate — then rewrite the flagged sentences before you submit.

Want section-by-section scans inside LaTeX? That’s Bibby Pro.

Explore More

AI Detector & Plagiarism Check — Free, no login | Bibby | Bibby AI