Turnitin

Turnitin is the world's most widely used plagiarism-detection and academic-integrity platform, adopted by tens of thousands of schools, universities and educators to check student work for originality. When a student submits an essay, Turnitin compares it against a massive database of academic papers, published content, websites and previously submitted student work, then produces a "similarity report" highlighting matching text and its sources.

In response to generative AI, Turnitin added AI-writing detection that flags passages likely produced by tools like ChatGPT — now a central feature as educators grapple with AI-assisted cheating. It also provides feedback and grading tools (Feedback Studio) that let teachers comment, grade and check integrity in one workflow.

Turnitin is primarily an institutional product — students almost always encounter it because their school requires submissions through it, rather than buying it themselves. Pricing is by institutional license, not consumer subscription.

Strengths: the largest comparison database in the industry (including student papers other checkers can't see), deep integration with learning management systems, and trusted grading tools. Weaknesses: its AI-detection accuracy is genuinely contested — false positives can wrongly accuse honest students, so results should never be treated as definitive proof; it's not available to individual students to pre-check their own work; and similarity scores require human interpretation (quotes and references inflate them innocently).

For educators and institutions upholding academic integrity, Turnitin remains the standard. Students wanting to check their own work before submission should use consumer tools like Grammarly's or Quillbot's plagiarism checkers instead.