Direct answer
Grammarly can check a draft for plagiarism and can also estimate whether text looks AI-generated, but it is not a Turnitin check. Its plagiarism checker compares your draft against web pages and academic sources, while its AI detector returns a likelihood estimate rather than an institutional AI score [1]. If your goal is to know what your professor's Turnitin report will show, you need a Turnitin AI writing report and similarity report, not a Grammarly estimate [1].
Does Grammarly Detect AI-Generated Content and Plagiarism in Your Writing?
Grammarly does both, but in two different ways that are easy to confuse. Its plagiarism checker scans your draft for passages that match existing web pages and academic papers, then highlights the overlapping text inside the editor [2]. Its AI detector is a separate feature that reads stylistic patterns — word choice, sentence rhythm, and how predictable each phrase is — and returns an estimate of how much of the text looks machine-generated [2].
The important distinction is what each result actually represents. A plagiarism match points to a specific external source you can open and inspect, which makes it verifiable evidence [2]. An AI likelihood estimate points to no source at all; it is a statistical judgement about style, and Grammarly presents it as a signal rather than a verdict [2].
Grammarly's own guidance is that AI detection results should be treated as one input among several, because the same detector can misjudge heavily edited human writing and lightly edited AI writing [2]. That is exactly why a Grammarly flag — or a clean Grammarly result — should never be treated as equivalent to an academic integrity finding [2].
How Accurate Is Grammarly's AI Detector Compared With Turnitin's AI Writing Detection?
Turnitin's AI writing detection works inside the similarity report and segments a document into portions it classifies as AI-generated versus human-written, then reports that as a percentage of the whole submission [3]. Because it operates on the same document your instructor uploads, its output is the number that actually appears in your institutional report [3].
Turnitin is also explicit about the limits of its own tool. When its confidence is low, it displays *% instead of an exact percentage, signalling a low-confidence result rather than a precise measurement [3]. Turnitin further states that a high AI score is not proof of misconduct and that its detector is built for academic prose, so it is not designed to evaluate informal writing or non-English text reliably [3].
Placed side by side, the practical difference is scope and consequence. Grammarly is a general writing assistant that estimates AI likelihood across many kinds of text [2], while Turnitin is an academic-integrity instrument tuned for student submissions and read by your institution [3]. A Grammarly result can tell you that something in your draft looks formulaic; only a Turnitin AI writing report tells you what the marker will actually see [3].
How Can Students Verify Their Real Turnitin AI and Similarity Scores Before Submitting?
Students generally cannot run an official Turnitin check on their own work, because submission and report access are controlled by the instructor and the institution [4]. That leaves a gap: you can polish a draft in Grammarly, but you cannot see the AI percentage that will land in your course's report until after you submit it [4].
A pre-submission check closes that gap by producing the same two documents instructors see — a Turnitin AI writing report and a similarity report — on your draft before it is finalised [4]. This matters most for the AI score, because Turnitin only surfaces an exact percentage above its confidence threshold and otherwise shows *%, so seeing the report is the clearest way to know how your writing is likely to be read [4].
It also matters for interpretation. A similarity report shows you which passages match external sources and how much of the document is affected, so you can distinguish genuine citation problems from common phrasing that happens to overlap [4]. Reviewing both reports together — AI detection and similarity — gives you the complete picture your instructor will work from [4].
Grammarly is a useful first pass, but it cannot show you the report your university will actually read. If you want that certainty before your deadline, turnitin0 delivers the real Turnitin AI and similarity reports on your own draft — the same two PDFs your professor sees — so you can fix what needs fixing while there is still time to act.
※ Turnitin0.com - Actual Turnitin AI Report Cover, Score, Flag And Similarity Summary
FAQ
Can Grammarly tell me my Turnitin AI score?
No. Grammarly's AI detector returns its own likelihood estimate based on writing patterns, not the percentage Turnitin reports [2]. Only a Turnitin AI writing report shows the figure your instructor will see [3].
Is Grammarly's plagiarism checker the same as a Turnitin similarity report?
They are different tools with different source databases and different outputs. Grammarly highlights matches against web and academic sources [1], while a Turnitin similarity report is the document your institution reviews and interprets [4].
Why does Turnitin sometimes show *% instead of a number?
Turnitin displays *% when its AI detection confidence is low, meaning the signal is not strong enough to report an exact percentage [3]. It is a low-confidence indicator, not a hidden score [3].
If Grammarly says my text is human, am I safe?
Not necessarily. Detectors disagree, and Grammarly itself treats its AI result as one signal rather than proof [2]. The only reliable way to know how your draft reads to your institution is to check it with the same report type your instructor uses [4].
Can I check my own draft with Turnitin before submitting?
Students normally cannot run an official Turnitin check themselves, since submission is controlled by the instructor [4]. A pre-submission check that returns the AI writing report and similarity report is the practical alternative [4].