Guide
What Is the Turnitin Similarity Report? The Document Behind the Badge
August 29, 2026
The Similarity Report is the full view of overlap: your paper with matching stretches marked, a list of sources those stretches came from, and filters that can change the number without changing a sentence, which is a different object from the small percentage on the assignment icon even though people use the two names as if they were one thing. The badge is a summary. The report is the evidence, and reading the evidence is the only way a surprising color becomes a story instead of a panic.
UC San Diego’s student note on why a similarity score can look high still sends you back to those highlighted sources rather than to a magic cutoff, and that is the right habit even when a classmate swears anything over 15 percent is a fail.
If you only wanted the percentage explained, that is already what the Turnitin similarity score is. This page is the report itself: what you see when someone opens it, what students often cannot open, and how it is not the AI writing indicator.
DetectGPT does not produce a Similarity Report. We score how AI-like writing reads, with a public paste or URL check, and we will not reprint the campus source list.
Check a draft on DetectGPT
If the draft came from ChatGPT, Claude, Grok, or Gemini, paste it here or drop in a public page URL and we'll score how much of it still sounds like a model, with a 3,000-word cap and no account in the way. We aren't Turnitin and we don't search a paper archive, so treat this as a self-check on rhythm rather than an official campus report.
Open the checkerAt a glance
| Factor | Quick answer |
|---|---|
| What it is | Highlighted paper plus matching sources |
| What it is not | An AI writing report or a grade |
| The badge | A summary of overlap, not the whole story |
| Who sees it | Often the instructor first, sometimes the student |
| Filters | Quotes, bibliography, small matches can swing it |
| DetectGPT | No source index, no originality report |
The report is the document, the score is the headline
When Turnitin finishes a file, it stores a report that lines your sentences up against the index and lists the places they matched, so a methods paragraph that everyone in the lab reused looks different from an uncited block lifted from a web page even when both move the similarity score by a similar amount. Instructors open that view in Feedback Studio or SpeedGrader. Students sometimes get a smaller version, and sometimes get only the icon, which is why arguing from a color you saw in Grades is weaker than asking to see the sources.
The color on the icon is a legend for how much of the paper overlapped, not a verdict, and what blue, green, and yellow mean is the chart for that legend. Open the report before you treat yellow as a crime or blue as original thought.
What is actually inside the report
Matching text is highlighted in the paper. Each highlight points at a source in the index: a web page, a journal, a student paper already in the archive, sometimes your own earlier upload. You can usually click through to see how much of the match is a quote, a cliche, or a lift. That machinery is the same heart as how the Turnitin plagiarism checker works, just shown as a document instead of a one-line definition.
Filters sit on top. Exclude quotes, exclude bibliography, exclude small matches, and the same file can slide from yellow to green without a rewrite. If two people tell two stories about one upload, ask which filters were on before you rewrite the week. Purdue OWL’s quoting and paraphrasing notes are still the cleanest reminder that a rewrite without a citation is still the source, which the report will often still find.
This is not the AI writing indicator
The Similarity Report is overlap with an index. The AI writing indicator, when a school enabled it, is a style guess about even sentences and safe wording, and it does not borrow this report’s highlights or this report’s colors. A paper can look quiet here and still look generated there, which is the split in does Turnitin detect ChatGPT. Pasting a brand-new model essay can leave the Similarity Report nearly empty because the index has nothing to point at.
Do not send a DetectGPT screenshot as a substitute Similarity Report. We do not search student papers or journals. We mark lines that still sound like a model so you can rewrite them, up to 3,000 words, without a school login.
Who gets to open it, and when
Many courses show students the report after the due date, or never, which is why a gray icon in Canvas can mean the report is still cooking rather than that it will never exist. That wait is how long Turnitin takes on Canvas. A resubmit can generate a second report on a second file, and the instructor may still be able to open the first, which is how to resubmit on Turnitin.
If you cannot open the report and the number looks wrong, ask to see the source list. Can Turnitin be wrong is the longer version of that conversation. The report is what makes the conversation specific instead of a fight about a crayon.
Mistakes that treat the report like a traffic light
Chasing 0 percent, ignoring a modest percentage that hides one stolen page, mixing the AI column into this document, and screenshotting a public checker as if it were Feedback Studio are the usual ways people argue with the wrong object.
- Read the sources, not only the badge.
- Ask which filters were on.
- Keep similarity and AI writing in two buckets.
- Cite even when you rewrote the sentence.
FAQs
- What is the Turnitin Similarity Report?
- The full overlap view: highlighted passages plus the list of matching sources. The percentage on the icon is only a summary.
- Is the Similarity Report the same as the similarity score?
- No. The score is the headline number. The report is the document that explains it.
- Does the Similarity Report show AI writing?
- No. That is a different indicator, when the school turned it on.
- Why can’t I open my Similarity Report?
- Many assignments keep it instructor-only, or delay it until after the due date. Ask the course. A gray icon can also mean it is still processing.
- Can DetectGPT give me a Similarity Report?
- No. We do not search a paper database. We score how AI-like a draft reads.
- Can filters change the report without me rewriting?
- Yes. Excluding quotes, bibliographies, or small matches can move the number and the highlights.
The bottom line
Treat the Similarity Report as the evidence and the icon as the headline, then open the sources before you panic or celebrate, because a color cannot tell a citation from a paste.
Keep that document away from the AI conversation unless someone is actually looking at the AI indicator, and use DetectGPT only when you care how the sentences sound rather than which web page they match.
The official overlap view still lives on the assignment. Everything here is a reading guide, not a reprint.
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