Direct answer
QuillBot is one of the most popular paraphrasing tools among students who want to bring their Turnitin AI score down, but relying on it is a gamble. Turnitin's AI writing detection is explicitly built to identify content that was generated by AI tools and then modified by AI paraphrasers or bypasser tools to evade detection [1]. In practice, that means QuillBot-rewritten text is not invisible to Turnitin — it can still be flagged as AI-modified. This guide explains how Turnitin treats QuillBot output, whether paraphrasing actually lowers your AI percentage, and how to check your real score before you submit.
Does Turnitin detect QuillBot paraphrasing?
Yes — in many cases Turnitin does detect QuillBot-paraphrased text. The AI writing report does not just give an overall percentage; it highlights the exact sentences that the model predicts were generated or modified by an AI tool, and paraphrased content counts as "modified" [2]. When you run QuillBot output through the report, those rewritten sentences can still surface as AI-flagged highlights.
Turnitin's detection model is trained to recognize the statistical fingerprints of LLM-generated text, and simple synonym swaps do not erase those patterns [2]. When QuillBot rewrites an AI-generated paragraph, the underlying sentence structure and word-choice probability still resemble AI output, so the report frequently flags it. This is why students are often surprised to see a high AI score even after paraphrasing.
That said, no AI detector is 100% accurate, and Turnitin itself emphasizes that the percentage should not be used as the sole basis for any action [2]. But the practical answer to "does Turnitin detect QuillBot?" is yes in a meaningful share of cases — especially for lightly edited or mechanically paraphrased text, which is exactly how most students use QuillBot.
Can QuillBot lower your Turnitin AI writing score?
Sometimes it lowers the score, and sometimes it does not — which is precisely the problem. The AI writing indicator reports an overall percentage of the document that may have been generated or modified by an AI tool, and "modified" explicitly includes rewritten content [3]. QuillBot can knock the percentage down on some sentences while leaving a large share of the document still flagged.
The indicator also uses percentage bands to help instructors interpret results: scores below 20% are displayed as *% rather than a single-digit number, while higher bands (20–40%, 40–80%, >80%) are shown with clear thresholds [3]. That means even a "lowered" score can land squarely in a band that draws an instructor's attention, and the sentence-level highlights remain visible inside the report.
In short, QuillBot does not reliably "clean" a document [3]. The outcome depends on the original AI text, the paraphrasing intensity, and the document's overall structure — and since you typically cannot see your own report, you rarely know which outcome you got until after submission.
How can you check your Turnitin AI score before submitting?
Here is the catch: as a student, you cannot self-check a paper inside Turnitin without uploading it to an official assignment created by your instructor, unless your institution has enabled Turnitin Draft Coach [4]. Without Draft Coach, your ability to preview scores depends entirely on your instructor's assignment settings.
And many assignments do not help: if resubmissions are disabled, your first upload is final, and there is no way to check beforehand through the official system [4]. Even where resubmissions are allowed, you are limited to a small number of attempts and may face 24-hour waits between reports.
That is exactly why a growing number of students check their draft with a real Turnitin AI and similarity report service before submitting [4]. A pre-submit report shows the same instructor-facing data — the overall AI percentage and the sentence-level flags — so you can see whether QuillBot actually did its job while you still have time to fix it.
Because Turnitin only shares the AI writing indicator with instructors, you usually cannot see your own score until it is too late. Turnitin0 gives you the same real Turnitin AI writing and similarity reports before you submit — upload your QuillBot-edited draft and see exactly what your instructor would see, in minutes, with no subscription.
※ Turnitin0.com - Actual Turnitin AI Report Cover, Score, Flag And Similarity Summary
FAQ
Does Turnitin detect QuillBot?
Yes, in many cases. Turnitin's AI writing detection is designed to identify text that was generated by an AI tool and then modified by an AI paraphraser or bypasser, and QuillBot-rewritten sentences can still appear as highlights in the AI writing report [1].
Can QuillBot get your Turnitin AI score to 0%?
Not reliably. QuillBot can lower the percentage on some sentences, but it often leaves AI-modified segments flagged, and results vary unpredictably from document to document [3].
Can students see their own Turnitin AI score?
Usually not. The AI writing indicator is visible only to instructors and administrators, and students cannot self-check inside Turnitin unless Draft Coach is enabled or the assignment allows resubmissions [4].
Is QuillBot the same as an AI humanizer?
No. QuillBot is a general paraphrasing tool, while Turnitin explicitly targets AI-paraphrased and bypassed text [1]. A dedicated humanizer is designed to rewrite AI text so it no longer carries the statistical patterns the detector looks for [2].
What should I do if my QuillBot text is still flagged?
Run your draft through a real Turnitin AI and similarity report before submitting, then rewrite the highlighted segments yourself or with a proper humanizer so the final version reads naturally in your own voice [2][4].