After you submit an assignment, your tutor uploads it to Turnitin, or your LMS sends it automatically. Within a few minutes — sometimes an hour for long papers — a coloured percentage appears next to your submission. On Blackboard, Moodle or Canvas, it’s usually a small square with a number in it. Click it, and the full Similarity Report opens.
Your first time seeing one can feel strange. A big red 34% staring back at you is enough to make anyone’s stomach drop. Take a breath. That number needs interpretation before it means anything.
What the Percentage Actually Means
The overall similarity percentage tells you what fraction of your text matches something in Turnitin’s database: other student papers, websites, journal articles, books. That is all it tells you. It does not say “this percentage of your essay is plagiarised.”
There Is No Magic Safe Number
Universities sometimes mention rough thresholds — under 20%, say — but these are guidelines, not rules. A 5% score with one badly paraphrased paragraph and no citation is a bigger problem than a 28% score made up of your reference list, quoted definitions and common phrases. Your marker looks at what matched, not just the total. So a high number is a prompt to investigate, not a verdict.
Reading the Match Breakdown
The report lists every source your work matched, ranked by how much text it shares with your paper. Click any source and Turnitin highlights the matching passages in colour — each source gets its own shade, which is why a heavily matched paper looks like a rainbow.
For each match, look at three things:
- The size of the match. A 1% match from a source is usually a phrase or two. A 12% match from one source is a whole section you need to look at.
- The colour-coded passages. The highlighted chunks show exactly which sentences overlap. Read them alongside the source, not on their own.
- Whether the match is continuous. Ten separate three-word matches scattered through the paper are normal. One unbroken paragraph of matching text is not.
This is the real work of reading the report: going match by match and deciding whether each one is legitimate or a problem.
Filters and Exclusions: Clean Up the Report First
Turnitin lets your marker exclude certain things from the score — and in many universities, you can apply these filters yourself before the final submission. The standard exclusions are:
- Bibliography. Your reference list will match other papers citing the same sources. Excluding it usually drops the score several points.
- Quoted material. Properly marked quotations match their sources by definition. Excluding them shows your actual problem areas.
- Small sources. Tiny matches — a few words here and there — can be filtered out by word count or percentage thresholds.
One caution: exclusions can also raise your score. Remove a large bibliography from the denominator and the remaining matches become a bigger slice of what’s left. That’s fine — it gives a more honest picture of the body text, which is what actually gets judged.
Similarity Reports vs AI-Writing Detection
These are two separate reports, and confusing them causes unnecessary panic. The similarity report measures text overlap with existing sources. The AI-writing report estimates how much of your text was likely generated by AI tools — it runs on the same submission but uses a completely different method, and it appears as a separate tab or section.
They need different responses. A high similarity match is fixed by paraphrasing, quoting or citing. An AI-writing flag is about how you wrote the text in the first place — rewriting a flagged paragraph by hand is the only real fix.
The Usual “False Alarm” Matches
Before you start rewriting, check whether your worst matches are actually problems. These four show up constantly and usually need no action:
- The reference list. Dozens of citations will match the original papers they describe. Exclude the bibliography and watch the score fall.
- Common academic phrases. “The results suggest that”, “a growing body of literature”, standard terminology in your field — these match thousands of papers and nobody marks them down.
- Assignment brief templates. If your department’s brief included headings or instructions that students reuse, whole sections match across every submission. Your marker knows.
- Your own earlier drafts. If you submitted a draft to the same portal, or resubmit after a first attempt, Turnitin may match your new file against your old one. Some universities configure this away; if not, it looks like self-plagiarism but usually gets noted and ignored. Mention it to your tutor if the score looks odd.
If your big matches are all in this category, your report is fine and you can stop worrying.
How to Investigate a High Match, Step by Step
When a match survives the false-alarm check, work through it properly:
- Click the source and read the original. See the passage in context before judging your version of it.
- Compare side by side. Is your text structurally the same with swapped words, or genuinely rewritten? Swapped words are patchwriting — still plagiarism.
- Check your citation. Did you cite this source at the point you used its ideas? A missing citation turns honest writing into a flagged match.
- Ask why it matched. Was it a quotation you forgot to mark? A paraphrase that stayed too close? An idea you absorbed and forgot to attribute?
- Decide the fix. Each cause has its own repair, covered below.
This takes twenty minutes for a typical essay. That’s a lot less than a misconduct panel.
Fixing High-Risk Matches
Paraphrase Properly
Real paraphrasing means digesting the idea and writing it from scratch, not running the source through a synonym swap. Read the passage, look away, and explain it in your own words as if to a friend. Then check: if you can’t reconstruct the original sentence from yours, you’re probably safe. Our guide to paraphrasing vs quoting walks through this with worked examples.
Here’s the difference. Source: “Sleep deprivation impairs decision-making under uncertainty in financial traders.” Patchwriting: “A lack of sleep harms traders’ decisions when facing uncertain financial situations.” Same skeleton, new adjectives — still plagiarism. Genuine paraphrase: “When traders don’t sleep enough, their judgement on risky investments suffers (Harrington, 2023).” Different sentence shape, same idea, cited.
Quote Correctly
If the author’s exact wording matters — a definition, a striking line, a legal clause — quote it rather than twisting it. Use quotation marks (or a block quote for longer extracts), name the author, and add the page number if your referencing style requires one. A correctly formatted quotation is a match Turnitin will show and your marker will accept without a second thought.
Add Missing Citations
Sometimes the writing is yours but the idea came from somewhere. That sentence about the 2021 housing study, the statistic on dropout rates, the three-stage model you summarised — if it came from a source, cite it at the point of use, not three paragraphs later. Most students find that half their “high” matches disappear once the citations are actually in place. If you need a refresher on habits that keep you out of trouble, our 7 plagiarism tips for students cover the daily workflow.
A Note on Writing from Scratch
Paraphrasing and citing fix the report. But if a draft was mostly generated by an AI tool or stitched together from sources, no amount of editing makes it your work — and modern AI-detection makes that gamble worse every semester. The honest fix is slower but simpler: write your own argument, support it with cited sources, and let the report confirm it. For guidance on polishing a genuinely written draft, our essay proofreading checklist covers the final pass.
For an authoritative reference on what counts as plagiarism and how to avoid it, Purdue OWL’s avoiding plagiarism guidance and Harvard’s Guide to Using Sources are the two resources tutors themselves recommend.
Checklist Before You Resubmit
Run through this on your final draft before it goes anywhere near the portal:
- Bibliography excluded from the report (or mentally discounted)
- Quoted material marked and excluded where your university allows
- Every large match from one source investigated and either fixed or cited
- No patchwritten paragraphs — each paraphrase rewritten from scratch
- All statistics, studies and borrowed ideas cited at the point of use
- AI-writing report checked separately if your university runs it
- Your own earlier draft matches noted, in case of resubmission overlap
Reading a Turnitin report is a skill, and like any skill it gets fast. The first time takes an hour; by your third essay you’ll spot the false alarms in minutes and know exactly which paragraphs need work.
Get a Second Pair of Eyes Before You Submit
If your report comes back with matches you can’t untangle — or you’ve already been flagged and need to fix a draft fast — The Pen Master can help. Our plagiarism and AI-removal service rewrites problem passages properly, adds the missing citations, and gets your draft submission-ready without the stress. Message us on WhatsApp at +49 1521 3962850 or send your draft through the contact form on thepenmaster.com for a quick quote.