iThenticate vs Turnitin: Which Plagiarism Checker is Right for You? (2025)

Both iThenticate and Turnitin are plagiarism detection tools owned by the same parent company — but they serve very different purposes, check against different databases, and are appropriate for different stages of academic work. If you are an Indian PhD scholar preparing your thesis or submitting to a journal, knowing which tool your institution uses, what each score actually means, and which produces a more accurate result for research-grade writing is essential knowledge before you submit. This comparison covers the key differences, the database sizes, how AI detection compares, pricing and access, and — most importantly — which tool is right for your specific situation.

Contents

• What is iThenticate?
• What is Turnitin?
• Key Differences: iThenticate vs Turnitin
• Which is Right for Your Situation?
• Our Recommendation
• Conclusion

What is iThenticate?

iThenticate is a plagiarism detection platform built specifically for the research and publishing environment. Owned by Turnitin LLC since 2014, iThenticate is designed for researchers, journal editors, PhD supervisors, and research institutions — not for classroom use. Its primary use cases are pre-submission manuscript screening, PhD thesis review, and academic grant application checking.

The platform’s database contains over 90 million journal articles and content from more than 1,500 academic publishers, including access via CrossRef, Elsevier, Springer, and MEDLINE. iThenticate powers the Crossref Similarity Check programme — the tool used by thousands of international journals to screen every manuscript before it enters peer review. Academic publishers globally do not accept Turnitin reports; they require iThenticate (or CrossCheck) reports instead.

A key feature that matters for Indian PhD students: iThenticate does not by default store your submitted document in its database. Your thesis or manuscript is checked but not added to the pool of documents against which other researchers’ work will be compared — a significant privacy protection for research in progress.

In July 2024, iThenticate launched version 2.0, which added AI writing detection to the similarity report. This feature is available only to institutional subscribers. Individual account users — who can create free accounts and purchase per-submission credits — do not have access to the AI detection layer.

What is Turnitin?

Turnitin is the dominant plagiarism detection tool for educational institutions worldwide. Designed primarily for classroom assignments, coursework, and student submissions at the undergraduate and postgraduate level, Turnitin is deployed through learning management systems (LMS) such as Moodle, Blackboard, and Canvas. The platform is used by thousands of Indian universities for routine assignment submission.

Turnitin’s database is substantially larger in certain dimensions: it includes approximately 47 billion web pages, 1.9 billion previously submitted student papers, and over 190 million published articles. The student paper database — which iThenticate lacks — is Turnitin’s most distinctive feature. If a student submits work that is substantially identical to a paper previously submitted by another student anywhere in the Turnitin system, the similarity check will flag it.

Since April 2023, Turnitin has included an AI writing detector. As of August 2025, the system has been updated three times: AIW-1 (April 2023), AIW-2 (December 2023), and the addition of AI Rewriting detection (AIR-1, July 2024) and AI bypasser detection (August 2025). The AI detection feature is available to all institutional subscribers as part of the standard Turnitin platform.

Unlike iThenticate, Turnitin stores submitted documents in its student database by default. Students can opt out of repository inclusion in some configurations, but this depends on how the instructor has configured the assignment. For PhD thesis submissions through Turnitin, some institutions exclude the document from the repository — check with your research office.

Key Differences: iThenticate vs Turnitin

The database difference matters more than it looks

A study published in a peer-reviewed scientific journal found that when the same set of documents was submitted to both platforms, iThenticate returned a mean similarity score of 8.30 per cent while Turnitin returned 12.10 per cent. This is not because one tool is more lenient — it is because the databases they check against are different, and the documents in each database create different matches. An Indian PhD thesis on a field well-represented in the journal literature may return a meaningfully different score depending on which tool is used.

AI detection: iThenticate 2.0 vs Turnitin

Turnitin’s AI detection is more mature and more widely deployed — it has been updated four times since April 2023 and is available to all institutional subscribers. iThenticate’s AI detection, introduced in July 2024, is newer and only available to institutional subscribers. If your institution uses iThenticate for your PhD thesis, confirm whether they have upgraded to the 2.0 version before assuming the report you receive contains an AI score.

For a thorough explanation of how Turnitin’s AI detector works and what the AI percentage means, see Why Your Turnitin Score Changes — and What Indian PhD Students Must Know.

Which is Right for Your Situation?

The answer depends on what stage of academic work you are at and what the output is for.

Use iThenticate if:

• You are submitting a manuscript to an international journal. Journals require iThenticate (or CrossCheck) reports. A Turnitin report will not be accepted.
• Your institution’s anti-plagiarism cell uses iThenticate for PhD thesis review. Many Indian central universities, IITs, and NITs use iThenticate because of its stronger journal database. If your anti-plagiarism certificate must come from iThenticate, no other tool will substitute.
• You want to self-check your thesis before formal submission and need privacy. iThenticate does not add your document to a shared database, protecting your original research until it is published.
• You are a researcher submitting a grant application or conference paper. Research-facing institutions and funding bodies typically use iThenticate for research integrity screening.

Use Turnitin if:

• Your course instructor requires Turnitin submission. Turnitin is embedded in most Indian universities’ LMS platforms for coursework. There is no practical alternative if the assignment is configured for Turnitin.
• Your institution uses Turnitin for PhD thesis submission. Some institutions use Turnitin rather than iThenticate for thesis checking. The tool you must use is the one your institution has designated, not the one you prefer.
• You want your similarity score to also check against previously submitted student papers. If you are concerned about unintentional overlap with another student’s work from a prior year, only Turnitin’s database includes that content.

For Indian PhD scholars specifically

The UGC 2018 regulations do not mandate a specific tool — they require the use of “any globally accepted plagiarism detection software.” Both iThenticate and Turnitin qualify. The choice is made at the institutional level, not by the student. Contact your research office or supervisor to confirm which tool your institution uses for anti-plagiarism certification, and use that tool for your formal self-check.

Our Recommendation

For Indian PhD researchers who have the choice of either tool, use iThenticate for your self-check before final submission. The reasons are practical:

• iThenticate does not store your document, protecting your unpublished research from being flagged if another student or researcher submits similar content before your thesis defence.
• The journal article database is more representative of the literature in most research disciplines, giving a more accurate reflection of how your thesis will look to journal editors when you submit for publication.
• The iThenticate report is the format international journals recognise. Running your thesis through iThenticate before submission gives you early visibility into matches that will appear when you submit chapter derivatives as journal articles.

If your institution mandates Turnitin for the formal anti-plagiarism certificate, you will still need to complete that submission — the two checks serve different administrative purposes. Run iThenticate for research quality, Turnitin for institutional compliance.

Conclusion

iThenticate and Turnitin are both plagiarism detection tools from the same parent company, but they are built for different audiences and check against different databases. For Indian PhD scholars and researchers, the choice is rarely free — it is determined by your institution’s subscription and your target journal’s requirements. Understanding which tool produces which score, and why the same document can return 8 per cent on one and 12 per cent on the other, ensures you interpret your results accurately and avoid misreading your similarity score as an absolute measure of originality.