Claude detection

Can Claude writing be detected?

Claude writes the most human-sounding writing of the major models — which is exactly why we keep dated corpora of its output and tune against each generation. Harder does not mean impossible. Here's what still gives it away.

What to look for

What Claude writing tends to sound like.

No single word proves anything — it's the pattern. These are the habits our scanner weighs when Claude-style text comes through:

Measured, flowing writing

Long graceful sentences with careful hedges — like a thoughtful editor who never tires.

Tidy takeaways

Each section lands on a neat little lesson. Real writing sometimes just stops.

Structured empathy

Acknowledge, reframe, resolve — the same emotional arc applied to any topic.

Polish that never frays

Even "casual" Claude keeps perfect grammar and balanced clauses. Actual casual writing doesn't.

Sentence lengths, one paragraph — even Claude hums

A person. Long thought, short one. Punch.

A model. Same-length sentences, marching in step.

Claude varies more than most models — the hum is quieter, which is why the scanner reads it together with phrasing and predictability instead of alone.

See it marked

The scanner shows you, sentence by sentence.

Paste a draft and the AI-leaning lines get marked right in your text. Here's the kind of thing that lights up:

Example — Claude's essay voice, marked by the scanner There's something quietly remarkable about the way small habits compound — not dramatically, but steadily, in ways we rarely notice until much later. I skipped the gym twice last week and honestly the guilt did more damage than the missed workouts. What begins as a five-minute routine becomes, over time, the architecture of a life.
The honest part

If Claude sounds so human, how would anyone name it?

They can't, reliably — and that's the point. The more natural the model, the less sense a brand-name verdict makes, because its style overlaps real writing more. So we don't play that game. ScanForAI measures degree and location: how strongly a text reads machine-written and which passages carry it. On a part-Claude, part-you document, that's the difference between a useless average and a marked-up draft you can actually fix.

Degree and location

Paste a part-Claude, part-you document and the heat-map shows where the machine voice sits — the useful answer when no brand label is honest.

Scan a text free

Nothing is stored on anonymous scans.

FAQ

What people actually ask.

Is Claude harder to detect than ChatGPT?

In our testing across dated corpora, Claude's default voice reads more natural than most models' — fewer stock phrases, better rhythm. That lowers heuristic scores, which is why our deep analysis (a trained language model) matters most on Claude-style text. Unedited Claude still gets caught; lightly-edited Claude is genuinely hard, for everyone.

Does Claude watermark its text?

No. Anthropic ships no public text watermark, and there's no hidden marker in Claude output. Detection is pattern-reading — statistical, probabilistic, honest tools say so.

Can Turnitin detect Claude?

Turnitin doesn't disclose per-model performance, and independent testing on newer models is thin. Treat any single flag — theirs or ours — as a starting point, not proof. Our per-line breakdown gives both sides something concrete to discuss.

Why does Claude sound so human?

Anthropic tuned it hard for natural register: varied sentence length, fewer formulaic transitions, a warmer voice. The habits that remain are subtler — relentless polish, tidy takeaways, hedged balance — and those are exactly what our scanner weighs.

Is there a free Claude detector?

This one — paste up to 20,000 characters anonymously, free, nothing stored. It's tuned against dated corpora of each Claude generation, and a free account adds the full pattern breakdown and deep analysis.

Check a text right now — free, nothing stored. Open the scanner →
AI detection is not 100% accurate. Every result is an estimate from writing patterns and can be wrong both ways. Never use it as the sole basis for a decision about a person, and never to accuse.