There is no single acceptable AI score on Turnitin. Turnitin does not set a pass mark, and each university decides how to use the result. In practice, 0% or an asterisk (1% to 19%) is rarely acted on, while scores of 20% and above may lead to a conversation with your tutor, not an automatic penalty.
Students often ask for a magic number. The honest answer is that it depends on your university, your module’s AI policy and what the highlighted text actually is. What we can do is explain what each range means, how Turnitin itself treats them and what usually happens next.
For the mechanics behind the score, read Turnitin AI detection explained.
What AI score is acceptable on Turnitin?
Turnitin does not publish an acceptable threshold. It says the AI percentage should not be the sole basis for action. Your university’s academic integrity policy decides what happens. If your module bans AI use, any confirmed AI text can be a problem; if it allows disclosed use, a higher score may be fine.
That is why two students with the same score can have different outcomes. Always read your module handbook’s AI section. If it is silent, ask your tutor.
What does each AI score range mean?
0% means no AI was detected. An asterisk means some AI was detected in the 1% to 19% range but Turnitin withheld the number. A blue percentage from 20% upward is a scored estimate of how much qualifying prose looks AI-generated. A dash or exclamation mark means the file was not scored.
| Score | Meaning | What usually happens (estimate, varies by university) |
|---|---|---|
| 0% | No AI writing detected | Nothing |
| *% (1% to 19%) | Some AI detected, number hidden as unreliable | Rarely acted on alone |
| 20% to 49% | Moderate share of prose flagged | May prompt a conversation or request for drafts |
| 50% and above | Most qualifying prose flagged | More likely to lead to a formal review, depending on policy |
| Dash or ! | Not processed or error | No AI evidence either way |
Remember that only long-form prose counts. Bullet points, tables, code and the reference list are excluded, so the percentage is of the qualifying text, not the whole file.
Why do scores below 20% show an asterisk?
Since July 2024, Turnitin has withheld the score and highlights for results between 1% and 19%, stating this is to avoid false positives. An asterisk is Turnitin signalling that its low-range output is not reliable enough to show as a number.
If your report shows an asterisk, you have not been accused of anything. Any policy treating an asterisk as evidence is relying on a number Turnitin chose not to publish. If you were flagged at a higher level and wrote the work yourself, read Turnitin AI false positives.
Do universities set an AI score limit?
Some departments set informal guide figures, but most published policies avoid a fixed percentage and say detector output alone is not proof. Several universities, including Curtin University from 1 January 2026, have switched Turnitin’s AI detection off entirely while keeping similarity checking.
Turnitin also says the score deliberately undercounts. Its FAQs give the example that a document scored at 50% could contain as much as 65% AI writing. Universities that understand this tend to treat the number as a prompt for discussion, not a verdict.
What happens if your AI score is high?
Usually your tutor will look at the highlighted passages and may ask to discuss the work or see drafts. Turnitin’s guidance describes a high score as a starting point for a conversation. Be ready with your version history, notes and an explanation of how you wrote it.
Keep the AI score separate from the similarity score. They measure different things; see Turnitin similarity report explained.
How can you check your AI score before submitting?
Students cannot see Turnitin’s AI indicator in the normal submission flow. An independent pre-submission service can send you the AI writing report and similarity report before your deadline, so you can review any flagged passages with time to spare.
Our step-by-step guide covers every option: how to check your Turnitin score before submitting.
Does the AI score work the same in every subject?
No. Subjects with formulaic writing, such as lab reports, nursing reflections or legal problem answers, can produce different AI patterns from discursive essays. Turnitin’s model is trained on academic writing broadly, but tutors in structured subjects often read AI scores with more caution because standard phrasing is expected.
Length also matters. Turnitin needs at least 300 words of qualifying prose and accepts up to 30,000 words for an AI report. A 310-word reflection behaves very differently from a 10,000-word dissertation chapter, because short documents get blunter predictions.
Language matters too. Turnitin’s AI detection covers English, Spanish and Japanese, with Modern Standard Arabic added in August 2026. Work in other languages does not receive an AI score.
Can your AI score change if you resubmit?
Yes. Turnitin updates its AI model several times a year and does not rescore past submissions. If you or your tutor resubmit the same document after an update, the AI score can come back different. A score is a snapshot of one model version, not a permanent label.
This is another reason not to treat a single percentage as definitive. If you are worried about a result, look at the highlighted passages and your drafts. If you make edits, check the new version before final submission so you are not surprised by a changed number.
How should you talk to your tutor about an AI score?
Ask to see the report, listen to the concern, then walk through how you wrote the work using your drafts and notes. Explain any tools you used and whether they were permitted. Keep the conversation factual. Most tutors want to understand your process, not to catch you out.
- Bring version history from Google Docs or Word.
- Have your notes and reading list to hand.
- Be ready to explain your main argument without the essay in front of you.
- Ask what your university’s policy says about AI scores as evidence.
If you think the score is a false positive, read Turnitin AI false positives before the meeting so you understand the common causes and can explain them clearly.
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Frequently asked questions
Is 20% AI on Turnitin bad?
20% is the lowest score Turnitin shows as a number. It is not automatically misconduct. What happens depends on your university’s policy and the passages highlighted.
Is 10% AI acceptable on Turnitin?
A result between 1% and 19% shows as an asterisk, not a number. Turnitin considers that range unreliable, so it is rarely acted on alone.
Can I get 0% AI on Turnitin?
Yes, many human-written documents score 0%. A small asterisk result is also common and not a cause for concern on its own.
Does the AI score include my reference list?
No. Turnitin excludes bibliographies, lists, tables and code from the AI score. Only long-form prose counts.
Is the AI score part of the similarity score?
No. Turnitin states the two scores are independent and do not affect each other.