If you write or edit content, you need to check that the finished draft is about the subject you set out to explain. Comparing a draft's meaning against a category you chose answers one question: does this writing read as being about the thing you intended? That is narrower than it sounds, and it is a question no other check answers.
The gap this fills
Existing checks miss a specific problem. A grammar check finds errors. A term-based content score compares your page against ones performing for a query. An editor catches unclear writing.
None of them catches a piece that is competently written, correct, and about a slightly different subject from the one intended. That happens constantly, because writers drift toward what is easiest to explain rather than what the reader needed.
The three findings you get
Your category is the nearest match. The writing does what you intended. Nothing to do.
Your category appears, but below others. The piece covers the subject while spending more of its length elsewhere. Usually a structural issue: the opening is about something else, or a background section grew.
Your category is absent from the list entirely. The writing is about something else. This is the finding worth the exercise, and it is nearly always invisible from inside the draft.
A worked example
Take a page written to help manufacturers choose a freight forwarder. You select an audience category for manufacturing operations.
The report returns freight and logistics services as the nearest category, several shipping categories after it, and manufacturing operations well down the list.
Reading the draft with that in mind, the cause is usually visible. The opening explains how forwarding companies are organized. The licensing section lists the accreditations forwarders hold. The pricing section explains how forwarders build a quote.
Every section is written from the supplier's perspective. It is accurate and it is addressed to the wrong person. A manufacturer wants to know which incoterms to insist on, what a reasonable rate looks like on their lanes, and how to tell a forwarder who will handle a customs hold from one who will not.
That is an editorial diagnosis a similarity comparison can prompt and cannot make for you. The number said the writing was about forwarders; the judgment about who the page is for is yours.
Using the phrase list properly
The report separates phrases present in your draft from phrases associated with the category that are absent.
Read the absent list as a description of what writing about that category usually involves, and ask which of them you have a genuine reason to discuss. Some will be irrelevant to your particular piece.
Inserting terms to move the number does move it, and it produces worse writing every time. The measurement cannot tell a phrase used because it belonged from one added to raise a score. If you cannot write a full sentence that a reader would benefit from reading, the phrase does not belong.
When to run it
Before publication, when there is still time to restructure. A similarity check on a published page tells you something you can no longer easily act on.
Useful moments: after a first draft and before editing, when a piece feels wrong and nobody can say why, when comparing two versions, and when several pages follow one template and you want to know whether they are distinct.
That last case is a good use. Location or service pages built from a template often return nearly identical nearest-category lists, which is a direct measurement of the problem with the approach.
What the result cannot tell you
- Whether the writing is accurate. A confident, wrong passage can closely match its subject.
- Whether it is good. A dull piece firmly about its subject scores well.
- Whether it will rank or be cited. No engine is involved in producing the number.
- Whether it is complete. A short piece can score higher for similarity than a thorough one covering more ground.
The input limit is 8,192 bytes, so a long article is checked in sections whose results do not combine into one score. Checking sections separately is often more useful anyway, since it identifies which part drifted.
Run the comparison once you have a draft to review. Investigate a mismatch against the brief so any revision improves the intended explanation.
See how the comparison is produced, checking a draft against its category, or how taxonomies help review a draft.