Direct answer
Grammarly's AI checker and Turnitin's AI writing detection are not interchangeable: they are separate tools built on different detection models, and a low or 0% Grammarly result does not reliably predict your Turnitin AI score. Because each detector is trained on its own data and tuned for a different purpose, the same essay can score cleanly in one tool and get flagged in the other [1]. If your goal is to know what your instructor will actually see, only an official Turnitin AI writing report can tell you that [1].
Can Grammarly's AI Checker Predict Your Turnitin AI Score?
The short answer is no — and the gap can be surprisingly large. Grammarly's AI checker and Turnitin's AI writing report are produced by independent systems with separate training data, detection models, and scoring logic [2]. A clean Grammarly result is a useful signal, but it is not a guarantee that Turnitin will agree with it.
Turnitin's detector is built specifically for academic submissions, so it is calibrated against the kind of writing students actually hand in. The AI writing report shows an overall percentage of the document that may have been generated by AI and highlights the specific sentences Turnitin's model flagged [2]. Grammarly does not reproduce that model, which is why its verdict cannot substitute for the real report.
In practice, students see mismatches in both directions. Grammarly sometimes flags passages that Turnitin accepts, and it sometimes reports 0% on text that Turnitin later flags as AI-written [2]. The safe way to read any non-Turnitin check is as background information only, never as a pass for submission.
How Do Grammarly and Turnitin Differ in How They Detect AI Writing?
The two tools were designed for different jobs. Grammarly's AI checker is a consumer-facing feature inside a writing assistant, while Turnitin's detector operates inside the academic workflow where submitted work is assessed for integrity [3]. That difference shapes everything else, from training data to how results are delivered and interpreted.
Practical differences follow directly from that split. Turnitin's AI writing detection is tuned for student essays and is normally applied at the point of submission, and whether a student can preview their own AI report is controlled by the settings chosen by their institution [3]. Grammarly, by contrast, is a self-service tool anyone can run any number of times on the same document.
The way results are presented also differs. Turnitin gives an overall AI percentage alongside sentence-level highlights, and it expects that number to be interpreted by an instructor as one signal rather than treated as proof of misconduct [3]. Grammarly offers a simpler low/medium/high style readout that was never designed to sit on the same scale as Turnitin's report.
What Does an Official Turnitin AI Report Show That a Grammarly Check Cannot?
When a professor opens your submission, they do not look at a Grammarly score — they look at Turnitin's AI writing report and similarity report. Turnitin frames that report inside an academic-integrity conversation, with guidance for educators on how to interpret flags and discuss AI use with students instead of treating a percentage as a verdict [4].
The official report also combines signals a consumer checker never touches: an overall AI percentage, sentence-level highlights of the passages the detector suspects, and the similarity index that shows which sources were matched [4]. Together these give the full context an instructor uses when reviewing your work, and none of that context exists in Grammarly.
This is the gap that matters most before you hit submit. If you only run Grammarly, you are guessing at what will appear on your instructor's screen; if you run the actual Turnitin report, you see exactly what they will see when your paper is graded [4].
Grammarly is a helpful writing companion, but it was never designed to show you what your professor sees. For that, you need the real Turnitin AI and similarity report — and that is exactly what turnitin0 delivers. Upload your.docx,.pdf, or.txt file and receive the same Turnitin reports your instructor uses, with more than 100,000 real reports already delivered to students worldwide.
※ Turnitin0.com - Actual Turnitin AI Report Cover, Score, Flag And Similarity Summary
FAQ
Is Grammarly's AI checker based on the same technology as Turnitin?
No. Grammarly and Turnitin each train their own detection models on their own datasets, so the two tools can disagree about the very same paragraph [1].
If Grammarly reports 0% AI, is my paper safe from Turnitin?
Not necessarily. Detectors are probabilistic and can disagree with each other, so only an official Turnitin AI writing report can show what your instructor will actually see [2].
Can I check my paper with Turnitin before submitting the way I use Grammarly?
Usually not on demand. In most institutions, Turnitin's AI writing report is controlled by the instructor or administrator, which means students often cannot preview their own report whenever they want [3].
How does Turnitin display low AI scores?
In Turnitin's AI writing report, any score below 20% is shown as *% rather than as a single-digit number, and 0% is the only explicit low numeric outcome students typically see.
What is the fastest way to see my real Turnitin AI score before I submit?
Run your draft through a real Turnitin AI and similarity report service before submission, then review the flagged sentences and the similarity summary before you finalize your paper [4].