A custom Turnitin report is a Turnitin-style PDF where you, not an institution, decide what the final score looks like. In this guide we'll break down what the two percentages actually represent, when each setting makes sense, and how to pick the right number for your document.
The two percentages on every Turnitin report
Every Turnitin submission produces two distinct scores. Our custom Turnitin report generator exposes both so you can tune them independently:
- Similarity percentage — the share of your text that matches an external source (a website, journal, prior submission, or a phrase commonly used in writing).
- AI detection percentage — the share of your text that Turnitin's classifier believes was AI-generated (ChatGPT, Claude, Gemini, etc.).
What a “good” similarity percentage looks like
For academic submissions, most instructors are comfortable with 10–20% similarity. Higher numbers don't automatically mean plagiarism — quoted material, references, and common phrases all contribute. Lower numbers may look suspiciously clean for non-trivial topics.
Picking a custom similarity score for your report:
- 0–9% — squeaky-clean, great for short personal essays.
- 10–18% — realistic for most academic work.
- 19–28% — common in research-heavy papers with citations.
- 29%+ — typical only when many direct quotes are included.
What a “good” AI detection percentage looks like
Genuine human writing usually scores 0–20% AI. Heavily edited AI output lands around 30–60%. Unedited AI content trips at 70%+. For a realistic custom report, pick a number that matches the kind of author you want the report to portray.
When custom Turnitin reports actually make sense
- Previewing what your essay might score before official submission.
- Demonstrating Turnitin scoring mechanics to a class.
- Providing freelance clients with proof of originality.
- Comparing how citation styles affect similarity scores.
- Practicing paraphrasing skills with instant feedback.
Step-by-step: creating your custom report
- Open the Turnitin report generator.
- Drop in your PDF (up to 10MB).
- In the modal, pick your AI percentage (0%, *, or a preset).
- Enter your similarity percentage (0–100).
- Click Generate Report and wait ~10 seconds.
- Download both the AI and Similarity PDFs.
How the highlighting works under the hood
The generator extracts text from your PDF, identifies sentences that match the requested percentage band, and applies authentic Turnitin-style color-coded highlights — the same yellow, blue, pink, and green tones the real report uses. The result is a PDF that visually matches what your instructor expects to see.
Frequently asked
Can I change the score after generating?
Yes. Just close the modal, re-upload (or click Generate New Reports), and pick different percentages.
Will the highlighted sentences make sense?
Yes — the algorithm picks contiguous, sentence-aligned passages to mimic real Turnitin output, not random scatter.
Is creating a custom report free?
Always. See our free Turnitin report page for details.
Next steps
Try the custom Turnitin report generator now, or learn how to generate a Turnitin report in 3 steps.