Certaffy

AI-writing detection

Know what's written by AI.Prove what isn't.

Clear AI scores for education and business — from classrooms to content teams — always backed by highlighted evidence, never a bare verdict.

Check 3 score summaries/day up to 2,000 words — no signup

Free AI check

Check writing for AI — no account required

Paste up to 2,000 words for a score summary (3 score summaries/day up to 2,000 words). The full highlighted report unlocks with a free account — 3 full highlighted reports, then 1 score-only scan/day up to 800 words.

0 / 2,000 words

3 score summaries/day up to 2,000 words

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What you can do here

Detect AI writing

Context-aware scoring with highlighted evidence — not a single accusatory number.

Prove your own work

Evidence packs, draft history, and shareable reports for fair academic review.

Check content compliance

Style rules, URL scans, and batch review for business and institution teams.

Writing Coach

Shows what’s weak in your writing and why — you do the rewriting.

Common questions

No detector is perfect. Scores are probabilistic signals with color bands that separate low, review, and elevated AI writing signals. AI detection accuracy varies by the AI model used and is strongest on the most common generators. Treat all results as review aids, not proof of misconduct. Short text and heavy editing can reduce confidence.

Start with evidence — not a single number

Choose Education or Work, or try the free detector first.

Start free — no credit card required

Free account: 3 full highlighted reports, then 1 score-only scan/day up to 800 words. No account: 3 score summaries/day up to 2,000 words.