What AI detectors measure, and how to write so you read human on them

Every AI detector is a statistics engine with an opinion. It reads your text, measures things like how predictable the next word is and how much sentence length varies, and turns those measurements into a percentage. The pages below explain, one detector at a time, what each tool is known for, why ordinary human writing sometimes gets flagged, and how Humanize 360 approaches writing that is meant to be read on that platform.

Two things we will say on every page. First, no tool, including ours, can promise a result on any detector; the vendors update their models without notice and disagree with each other on the same text. Second, the signals detectors look for are also the things that make writing dull to read, so fixing them is worth doing regardless.

If you want to see the signals in your own text before reading about a specific detector, the free AI detector on this site shows eleven of them with a Human Score out of 100.

Detectors

• What GPTZero measures, and how to read human on it
• Originality.ai for writers: what agencies see and how to read human on it
• Turnitin's AI writing indicator: what it sees and how to read human on it
• Copyleaks AI detection: what it combines and how to read human on it
• ZeroGPT explained: what the percentage means and how to read human on it
• QuillBot's AI detector: the AI-refined category and how to read human on it
• Grammarly's AI detector: how a writing assistant judges its own users
• Winston AI: what it scores, including scanned pages, and how to read human on it
• Sapling AI detector: sentence-level scores and how business writing reads human
• Writer's AI content detector: chunked checks and how brand copy reads human

The signals most detectors share

• Perplexity: how predictable each word is given the words before it.
• Burstiness: how much sentence length and structure vary.
• Stock phrases and tell-words: "delve", "leverage", "in today's fast-paced world".
• Paragraph uniformity: every paragraph the same shape and length.
• Register signals: contraction rate, transition-word density, opener repetition.

How we write these pages

We describe each detector from its public documentation and from testing ordinary text against it. We do not claim to know its internals, we do not quote a pass rate, and we never use the words "undetectable" or "bypass" as a promise. What we can say is how the eleven signals in our own analyser relate to what each detector reports, and which Humanize 360 mode tends to help.

Common questions

Which AI detector is the most accurate?

None of them is reliable enough to act on alone, and they regularly disagree with each other on the same text. Each page explains what the detector is good at and where it produces false positives.

Can Humanize 360 guarantee my text passes a detector?

No, and you should be suspicious of any tool that says it can. We remove the statistical tells that detectors and readers notice and show you the eleven signals so you can judge for yourself.

Why does my own writing get flagged?

Careful, formal writing with even sentence lengths, few contractions and lots of transition words looks statistically similar to machine text. Non-native writers and students following a strict template are affected most. The detector pages explain which signals cause it.