Why the highlighted passages matter more than the percentage

Two essays can both score 68%. One has a single generated-looking page in the middle. The other has a faint signal spread across ordinary academic prose. The percentage treats them as the same case. The highlights do not.

A percentage has no location

The overall score answers “how strong is the signal on this document?” It does not answer “which lines should I read?” Without that second answer, a reviewer either waves the essay through or argues about a number nobody can point to.

Certaffy marks the passages behind the score and, on a full report, explains the risk on those passages, including possible AI paraphrase. You can disagree with a highlight. You cannot disagree usefully with a bare percentage, because there is nothing on the page to discuss.

The bands still matter as a sorting step:

• 0–29% — low signal. Highlights, if any, are optional reading.
• 30–74% — this is where the highlights are the assignment. Read each one with the sentences around it.
• 75% or higher — elevated signal. The highlights are the agenda for the meeting or the rewrite.

What to do with a highlight

Read the marked text in context. Then choose one of three outcomes:

1. It is the point. The passage does not sound like the writer, does not match the draft, or cannot be explained. Follow your review process.
2. It is a known trap. A quotation, a required formula, a legal line, or a very short fragment. Note that and move on. The false-positive guide lists the patterns that deserve this slower read.
3. It is mixed. Part of the paragraph is the writer’s, and part is not. Mark only the lines you will actually ask about. Mixed pages are discussed in how to review mixed writing.

A highlight can be wrong. An unmarked sentence can still be generated, especially after a person edits it. The highlight is the best place to start, not a map of every sentence’s origin.

Why the PDF should show the passages

A screenshot of “68%” is a poor record. A PDF that shows the score, the highlights, and the note you added is a file a teacher can share in a meeting or a team can store with the published article.

That report is part of Academic Pro ($9 a month, or $72 a year) and Business ($15 per seat a month, or $120 per seat a year). The free checker still shows a score summary, and a free account includes 3 full highlighted reports before it drops to a score-only scan.

Use the number last

Sort with the band. Decide from the passages, the draft, and the person who wrote the piece. If you only have time for one part of the report, make it the highlights.

Run a text on the free AI detector, then open the full report from Education or Work when you need the passages in a file you can keep.