Copy

An AI phrasing detector measures prose, not provenance.

The useful question about a generated draft is not whether a model wrote it. It is which sentences were assembled rather than written, because those are the sentences a reader skips.

Phrasing is not authorship

Detectors that claim to identify AI text are answering a provenance question with a style measurement, and the mismatch is why they disagree with each other and with reality.

Phrasing analysis avoids that error by not making the claim. It reports specific, countable properties of the prose, and lets an editor decide what they mean for this publication and this audience.

That distinction matters legally as well. A style score is a reasonable editorial input; it is a poor basis for accusing a writer.

The signals that survive editing

Five measurements hold up across formats, and each points at a different kind of problem.

  • Stock phrase density: transitions and verbs that signal a point without making one.
  • Hedge density: claims wrapped in qualifiers until they assert nothing actionable.
  • Overclaim density: the opposite failure, where absolutes appear without evidence.
  • Sentence-length variance: low variance means every sentence is a medium one, which reads as flat.
  • Opener repetition: too many sentences beginning the same way, which is a template artifact.

Why variance is the most useful number

Readers do not experience word choice the way editors do. They experience rhythm, and rhythm is variance: a short sentence landing after a long one, a fragment used deliberately.

Uniform length is the strongest visible signature of generated prose, because a model produces sentences of similar structural weight. Averages hide it, which is why the check reports spread rather than mean.

The fix is editorial and quick: cut one sentence to four words, let one run long, delete the transition that announces what the next paragraph will do. Variance returns and the paragraph starts sounding like a person.

Register matters more than the threshold

Legal writing should hedge, because qualified claims are accurate claims. Technical documentation should use the same noun for the same thing, which looks like repetition. Safety copy should be absolute where safety is absolute.

So the numbers are relative to the format. A report that treats every hedge as a defect will make legal copy worse, and a report that treats every absolute as an overclaim will make an instruction manual unreadable.

Set expectations per format rather than globally. Marketing landing pages have the highest tolerance for consequence-free prose; regulated claims have the lowest.

Editing with the numbers, not against them

Read the flagged paragraph and ask what it asserts. If the answer is nothing, delete it, and the counts fall without any word-level surgery.

If it does assert something, replace the stock verb with the specific action and the abstract noun with the thing itself. A sentence with a name, a number or a consequence in it is rarely flagged, because specifics do not come from a distribution.

Then re-run. The comparison between the first and second run is the useful artefact: it shows whether the editing changed the prose or merely rearranged it.

Where a person still has to read

No measurement of phrasing can tell you whether the argument is honest, whether the joke lands or whether a claim will be read as a promise by the audience it reaches.

For anything published under a company name, in a regulated sector or in front of a legal team, the numbers narrow the reading and a named editor signs the verdict.

That is the division of labour the tool is built for: measurement on everything, judgement where judgement is needed.

What this covers

  • Stock phrasing

    Counted per section so clusters are visible rather than averaged away.

  • Hedge and overclaim

    Both directions measured against the format's accepted register.

  • Rhythm spread

    Sentence-length variance rather than average length.

  • Opener repetition

    Identical sentence starts flagged within a paragraph.

  • Before-and-after

    Re-running after editing shows whether the prose actually changed.

Questions this page usually raises

Can this tell me if a text was AI-generated?
No. It measures phrasing properties that generated text tends to share. Plenty of human writing, especially templated copy, scores the same way.
Is a low score a guarantee of human authorship?
No. Editing removes these signals quickly. The score describes the prose in front of you, not the process that produced it.
How should thresholds differ by format?
Set them per channel: strict on marketing pages, looser on legal and technical documents where hedging and repetition are correct.
Does it check grammar and spelling?
It is not a grammar checker. The checks are about pattern, rhythm and claim shape, which is why it pairs with a copy edit rather than replacing one.
Do I need an account to measure a draft?
No. The analysis runs in your browser on whatever you paste, and nothing is stored unless you deliberately save the report.

AI phrasing detector

Run the checks, then decide who has to sign it.

The automated pass is free, needs no account and uploads nothing. Escalate to a named reviewer only where being wrong is expensive.