AI-text detection that tells you why.
One HTTP call returns a calibrated probability that text is AI-generated, and the exact signals that fired: buzzword density, stock phrases, uniform sentence rhythm, chat-UI artifacts. Most detectors hand back a bare number. This one hands back the evidence, so you can build a review UI a human can actually trust.
# first call, no signup curl -s https://tellcheck-api.munzzyy.workers.dev/v1/detect \ -H "content-type: application/json" \ -d '{"text": "your text here"}'
How it works
No magic, just measurable signals. The detector extracts deterministic features from the text (buzzword and stock-phrase density, per-language word lists, template rhythm, sentence-length uniformity, punctuation and structural patterns), feeds them to a calibrated model, and returns a probability, not a vibe. On text under 20 words, or text it detects as non-English, it does not score at all: it abstains and says why. That abstention is a feature, not a gap. A detector that refuses to guess on a one-line comment is more trustworthy than one that hands back a confident number anyway.
Live demo
Runs the real API on the free tier. Paste text and score it. Free-tier requests are metered per IP address, per day.
Why it is different
| Most detectors | Tellcheck |
|---|---|
| A bare 0 to 100 score | Probability plus the specific signals that fired |
| Guesses on any input, short or not | Abstains under 20 words or on non-English text, and says so |
| "Trust us" accuracy | Numbers we measured ourselves, on the benchmark page, honest limits included |
| Monthly subscription | Prepaid credits, no subscription, credits never expire |
| Account and dashboard to start | Free tier with no signup; a key when you need more |
Rows describing other tools are our own characterization, not a line-by-line audit of any one competitor. Every number on this page that is ours is marked as self-measured.
More than AI detection
The /v1/scan endpoint adds a text-integrity report to every
result: hidden Unicode (zero-width and invisible characters), bidirectional controls (the
Trojan-Source trick), and homoglyph spoofs (a Cyrillic letter hiding in a Latin word). It
can hand back a sanitized copy too. One call defends an LLM pipeline against both AI slop
and hidden-character injection. See the docs.
Integrate in one call
# free tier, no key curl -s https://tellcheck-api.munzzyy.workers.dev/v1/detect \ -H "content-type: application/json" \ -d '{"text": "your text here"}'
With a key, send Authorization: Bearer sk_live_... and a batch of up to 50 texts per call. Full reference in the docs.
Pricing
Prepaid credits, one detection each. Credits never expire. Buy more anytime; they add to your key.
Free tier: 25 detections a day, no account. Batch calls cost one credit per text.