How to Fix a High Similarity Score: 7 Proven Strategies (2026 Guide)

What counts as a high similarity score?

Before you start rewriting, it helps to understand what your institution actually considers a problem. Similarity scores are not the same as plagiarism scores — they measure how much of your text matches other published sources, including your own correctly cited quotations.

These thresholds are general guidelines. Always check your specific university's academic integrity policy — some institutions set the threshold as low as 10% for dissertations, while others allow up to 20% for coursework with heavy citation requirements. If you are unsure, ask your lecturer or supervisor before submitting.

Check your report before you start rewriting

The most common mistake students make is to start rewriting immediately without analysing where the similarity is coming from. Open your Turnitin report (or the report from your free plagiarism checker) and identify the following before touching a single sentence:

• 📌
  Which sections have the highest match percentage?

  Focus your rewriting effort on the top 3 flagged sections first — they account for the majority of your score.

• 📚
  Is the bibliography included in the score?

  Reference lists always match other papers verbatim. If the report includes your bibliography, that alone can add 5–10% to your score. Ask your institution to exclude it.

• 💬
  Are the matches from your own direct quotes?

  Quoted text with proper citation marks is not plagiarism, but it still adds to your similarity score. Reducing the number of direct quotes is one of the fastest ways to lower the score.

• 🔄
  Is any match from your own previous work?

  Submitting the same text you submitted for a previous assignment — even your own work — is self-plagiarism and will be flagged.

If you do not yet have access to a Turnitin report, you can run a preliminary check using our free plagiarism checker — it scans against Wikipedia, arXiv, PubMed, and Semantic Scholar and will flag the most obvious matches before you submit.

Strategy 1 — Paraphrase, don't just swap synonyms

This is the most important strategy and the one most students get wrong. Turnitin does not just match words — it analyses sentence structure, phrase patterns, and the order of ideas. Simply replacing individual words with synonyms (a technique sometimes called "spinning") will not lower your score because the underlying sentence structure remains identical.

Effective paraphrasing requires you to:

1. Read the original passage and close the source document.
2. Write the idea from memory in your own words, without looking at the original.
3. Change the sentence structure — if the original uses a passive voice, use active voice. If it lists items in a series, restructure as a paragraph.
4. Add your own analysis — connect the idea to your argument rather than just restating the source.
5. Cite the source — paraphrasing still requires a citation. Removing the citation does not fix plagiarism; it makes it worse.

Our free paraphrasing tool can help you restructure sentences quickly. Use it as a starting point, then edit the output to match your own voice and argument — never submit AI-paraphrased text without reviewing and adapting it yourself. For a deeper guide on this technique, read our article on paraphrasing without plagiarising.

Strategy 2 — Reduce direct quotes

Direct quotations are legitimate and necessary in academic writing — but they always increase your similarity score because they are, by definition, identical to the source text. Many students over-quote because it feels safer than paraphrasing, but most academic writing conventions actually discourage excessive quotation.

A practical rule of thumb: no more than 10% of your essay should be direct quotation. For a 2,000-word essay, that is 200 words of quoted text — roughly 4–5 short quotes. If you have more than that, convert the excess into paraphrases with citations.

Reserve direct quotes for three situations only: (1) when the exact wording of a definition is legally or academically significant, (2) when a particularly powerful or famous statement would lose impact if paraphrased, and (3) when you are analysing the language itself (e.g., in a literature essay).

Strategy 3 — Fix your citation formatting

Incorrectly formatted citations are one of the most common causes of unexpectedly high similarity scores. When Turnitin cannot identify a passage as a properly attributed quote (because the citation is missing or malformed), it treats the text as unattributed matching content and flags it as a potential match.

Common citation errors that inflate similarity scores include:

• ✗ Missing in-text citations for paraphrased ideas
• ✗ Direct quotes without quotation marks (Turnitin cannot identify them as quotes)
• ✗ Wrong author name or year in the in-text citation
• ✗ References in the bibliography that do not match in-text citations

Use our free citation cross-checker to validate every in-text citation against your reference list and catch mismatches before submission. It supports APA, Harvard, MLA, and Chicago styles. You can also use our free citation generator to generate correctly formatted references from scratch. For a complete guide to citation styles, see our article on how to cite sources correctly in APA, MLA, Chicago, and Harvard.

Strategy 4 — Exclude the bibliography from the score

Your reference list will always produce a high similarity match because it contains author names, journal titles, and publication details that appear verbatim in thousands of other academic papers. This is not plagiarism — it is correct academic practice — but it inflates your similarity score significantly.

Most Turnitin reports include an option to exclude the bibliography, quoted text, and small matches from the similarity calculation. If your institution's submission portal shows you the report, look for the filter options in the top-right corner of the Turnitin Similarity Report viewer. Enable "Exclude Bibliography", "Exclude Quoted Text", and "Exclude Small Matches (under 5 words)".

If you cannot access these filters yourself, ask your lecturer or module coordinator to apply them when reviewing your submission. A score that looks like 28% with the bibliography included may drop to 14% once it is excluded — well within the acceptable range.

Strategy 5 — Remove self-plagiarism

Self-plagiarism — reusing text from your own previous submissions — is flagged by Turnitin just as aggressively as copying from external sources. This surprises many students who assume that using their own work is always acceptable. It is not, unless you have explicit permission from your institution to reuse prior work (sometimes called "recycling" or "double submission").

If Turnitin flags matches against your own previous submissions, you have two options: rewrite the flagged sections entirely, or contact your module coordinator to explain the context and request permission to reuse the material with proper attribution.

For more on the different types of plagiarism and how to avoid them, read our comprehensive guide on how to avoid plagiarism in academic writing.

Strategy 6 — Rewrite your introduction and conclusion

Introductions and conclusions are the sections most likely to contain generic academic phrasing that matches thousands of other papers. Phrases like "This essay will argue that...", "In conclusion, it is clear that...", or "Academic research has shown that..." appear so frequently in student writing that they are almost guaranteed to produce similarity matches.

Rewrite your introduction and conclusion in a more specific, personal academic voice. Instead of generic framing sentences, open with a specific claim, a statistic, or a direct statement of your argument. This not only reduces your similarity score but also makes your writing more engaging and academically compelling.

Strategy 7 — Use a free plagiarism checker to verify before submitting

After rewriting the flagged sections, run your revised essay through a free plagiarism checker before submitting to Turnitin. This gives you a second opinion and helps you catch any remaining high-match passages that you may have missed.

Our free plagiarism checker scans your text against Wikipedia, arXiv, PubMed, Semantic Scholar, and CORE — the same academic databases that Turnitin draws from. While it does not replicate Turnitin's full database, it will flag the most significant matches and give you confidence that your rewriting has been effective.

For a broader comparison of free plagiarism checking tools, including which ones work best for different assignment types, read our guide to the 10 best free plagiarism checkers for students in 2026.

Frequently Asked Questions