Turnitin
An academic integrity platform for educational institutions, officially claiming cooperation with more than 16,000 institutions worldwide; AI writing detection is provided as an additional feature of Similarity Report and is only visible to teachers and administrators.
Updated: 2026-10-26
What is Turnitin?
Turnitin is an academic integrity platform for educational institutions, and the official states that more than 16,000 institutions worldwide have partnered with it. Its AI writing detection is not a standalone product but an additional feature on the Similarity Report. According to the official, it is only available to customers who have licensed Turnitin Originality, while iThenticate 2.0 customers need to access it via the AI writing add-on. Unlike the web-based detectors for individuals, the detection results of Turnitin can only be viewed by teachers and administrators, and no scores are displayed to students. The official also emphasizes that this percentage should not be the sole basis for teachers to assign grades or take disciplinary actions.
Who is it for?
- Colleges, universities, and primary and secondary schools that have purchased Turnitin Originality and wish to overlay AI writing detection on their existing plagiarism check process
- Research institutions and journal editorial offices that use iThenticate 2.0 to screen submitted papers, grant applications and dissertations
- Course instructors who complete the "submission-detection-feedback" loop in LMS platforms such as Moodle, Canvas, and Blackboard
- Administrators who need an institutional-level view: The official states that administrators can view aggregated AI scores and toggle the feature on or off by themselves
- Academic affairs and teaching teams concerned about false positive risks, with a feedback button available in the reports to report misjudgments
Key features
5AI writing indicator
After submission, the system splits the main text into overlapping segments, scores each segment individually, and then aggregates the scores to calculate the AI writing percentage of the entire document. Text suspected to be AI-generated or modified by evasion tools is highlighted in cyan in the report.
No specific scores displayed in the low range
To reduce false positives, the official does not provide numerical values or highlights for detection results in the 1%–19% range, only showing *%; it displays a gray -- when unable to process the content, and an exclamation mark (!) for processing failures.
False Positive Rate Control
The official stated that for documents where AI writing accounts for more than 20%, the false positive rate is controlled below 1%. Before each model update, more than 700,000 academic papers written before the release of ChatGPT are used for verification; to this end, a certain level of missed detection is actively accepted.
Model Coverage and Evasion Detection
The officially listed detectable models include GPT-4o, GPT-5 series, Gemini, Claude, LLaMA, Mistral, DeepSeek, Grok, etc. It can also identify text modified by AI rewriters or humanizers, with the latter only accepting submissions in English.
File Requirements and Language
Officially, documents submitted in English must be less than 100 MB, contain at least 300 words of prose, and not exceed 30,000 words. .docx, .pdf, .txt, and .rtf formats are accepted; non-prose content, code, and bullet points are outside the detection scope. Long-form texts in English, Spanish, Japanese, and Modern Arabic are supported. The LMS interface does not directly display AI scores; these must be viewed in the report.
How to use Turnitin
- Treat the AI writing percentage as a "clue for talking to students" rather than a conclusion – the official statement makes it clear that it does not make academic misconduct determinations and should not be the sole basis for grading.
- In practical operation, first look at the specific highlighted cyan paragraphs, then make a judgment combined with the course requirements and the writing process.
- this is far more reliable than just looking at a single percentage.
- Pay attention to the file threshold: assignments with fewer than 300 words or non-essay formats will not generate results.
- Short documents are also prone to an "all-or-nothing" judgment, while long documents are more suitable for positioning.
- The fact that the 1%–19% range does not display specific values is a trade-off made by the official to reduce false positives, so there is no need to resubmit repeatedly to pursue an exact number.
- historical assignments will only be detected after resubmission.
Traffic & popularity
Data month Sep 2026
Turnitin receives about 21.7M visits per month and ranks #2,090 worldwide.
Monthly visits
12 monthsTraffic sources
- Referrals46.6%
- Direct34.0%
- Search14.6%
- Mail2.1%
- Social1.5%
- Other1.2%
Top countries
- United States45.9%
- Australia11.5%
- India5.1%
- Peru4.9%
- Indonesia3.3%
Estimated from third-party traffic data.
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