As we all know it Quillbot gets detected by GPTZero quite often. However, the question that keeps popping up is, “Can Turnitin detect Quillbot?” The short answer is yes, it can. The longer answer is that the devil lies in the details. Keep reading to know more about it.
Why Quillbot gets detected by Turnitin?
The simple answer is that originally Quillbot was not made to bypass AI detectors. It came way before than ChatGPT. It used to be a simple paraphraser with different modes. If you look at it closely you would realize that DNA of Quillbot still remains, it is just that they have added some extra bells and whistles to it.
Recently they have added new modes like "Humanize" to jump on this AI humanizer train. However, they don't do a very good job of doing it.
Quillbot’s Data At A Glance
Now, let’s look at some interesting numbers. We tested 100 pieces of AI-generated text through Quillbot’s different modes and checked the output on Turnitin. The results were somewhat expected and indicated that Quillbot is not a silver bullet when you want to bypass Turnitin’s AI detection.
Below is the table containing key metrics for different modes of Quillbot paraphraser, how many samples we tested for each, their mean percentage detection by Turnitin, median score, minimum and maximum, success rate (≤20% AI score), and standard deviation. We have considered higher scores as "AI-like" which means a score of 100% means it is "AI-written".
| Quillbot mode | # Samples | Mean % | Median % | Min % | Max % | ≤ 20 % (success rate) |
SD % |
|---|---|---|---|---|---|---|---|
| Shorten | 11 | 45.3 | 0.0 | 0 | 100 | 54.5 % | 52.0 |
| Humanize | 11 | 45.4 | 13.0 | 0 | 100 | 54.5 % | 49.4 |
| Creative | 10 | 61.9 | 74.5 | 0 | 100 | 20.0 % | 40.7 |
| Expand | 12 | 69.4 | 90.5 | 0 | 100 | 16.7 % | 38.9 |
| Formal | 11 | 72.7 | 100.0 | 0 | 100 | 18.2 % | 39.7 |
| Standard | 12 | 73.6 | 100.0 | 0 | 100 | 25.0 % | 44.6 |
| Academic | 11 | 78.9 | 100.0 | 0 | 100 | 9.1 % | 34.9 |
| Fluency | 11 | 80.1 | 100.0 | 0 | 100 | 18.2 % | 40.0 |
| Simple | 11 | 87.4 | 100.0 | 0 | 100 | 9.1 % | 30.1 |
Quillbot Overall Stats (n=100)
- Mean Turnitin AI Score: ~68 %
- Median Score: ~90 %
- Texts ≤ 20 % (often “human-like”): ~25 %
Also Read: Can Winston AI detect Quillbot?
Interpretation
- On average, Quillbot only pushes one out of four AI-generated passages under 20% Turnitin detection, meaning ~75% of the content may still get flagged.
- Even its strongest modes—Shorten and Humanize—misfire around half of the time, scoring ~45% on average. That means if your aim is to consistently get below 20%, Quillbot’s reliability is questionable.
- Simple and Fluency modes are the worst performers, with average scores ≥80% (Turnitin flags them with 80 points out of 100).
- There’s also a high variance in every mode (standard deviation ~30–52%), so the same mode can give you a 0% detection on one piece of text and 100% on another.
Also Read: Can ZeroGPT detect Quillbot?
Which Modes Are Best at Bypassing Turnitin?
If we look at just the success rate (scores ≤20%), Shorten and Humanize modes do the best job (~55%). But that is not really great if you want consistent performance. Creative and Expand come somewhere in the middle; they do reduce the average score from raw AI text (which often scores 90-100%), but they don’t reliably push it below 20%.
Why Turnitin Has an Easy Time Detecting Quillbot?
Turnitin’s sophisticated detection algorithms likely include advanced machine learning models, stylometric analysis, and other statistical checks to detect rewriting methods that preserve meaning but still look like AI. Quillbot’s rewriting style is apparently well-known to these models. Additionally, large language models like Quillbot’s paraphraser generally generate text with low perplexity or burstiness, which are typical AI “fingerprints.”
No Guarantee & Ethical Risks
As we have seen in the table and points above, Quillbot does not guarantee a free pass. Even if it occasionally lowers your Turnitin AI score to 0%, it could shoot up back to 100% if you are unlucky.
Plus, there is another major consideration—ethics. Some universities interpret using AI-based rewriting as academic dishonesty, especially if you’re trying to mask the origin of an AI-generated content. If you get flagged and investigated, the consequences can be severe.
Single Opinion That’s Useful to You
In my own opinion, Quillbot is a decent tool for rewriting or polishing your text, but it’s not a dependable solution if your primary motive is to bypass Turnitin’s AI detection. If you want truly unique text, your best bet is to either write it yourself or use a dedicated AI humanizer like Deceptioner. That is the surest path to not getting tripped by Turnitin’s AI detective.
Frequently Asked Questions
Q1. Does Turnitin detect Quillbot’s paraphrasing in 2025?
Yes, it can easily detect it. Quillbot is popular, and Turnitin’s developers almost certainly factored in common rewriting behaviors.
Q2. Why isn’t Quillbot good for bypassing AI detection?
Because it doesn’t specifically aims to fool Turnitin. The rewriting is more about improving phrasing and removing errors rather than circumventing AI detectors.
Q3. Which are the best Quillbot modes for minimal AI detection?
Shorten and Humanize give about ~45% average score, and around half of it might slip under 20% detection. But it’s not a foolproof method.
Q4. Do big grammar checkers also hamper the bypass strategy?
Yes, advanced grammar checkers like Grammarly force the text into a cohesive style, which ironically can increase certain “AI-likeness” scores. So if you are purposely trying to bypass detection, grammar checkers might ruin the random variations you introduced.
Q5. Should I rely on Quillbot for big academic projects?
You can use it to refine your text, but do not rely on it as an AI bypasser. It’s risky, and Turnitin is constantly evolving its models.
The Bottom Line
If your only aim is to hide AI-generated text, Quillbot might help you partially but not reliably. On average, only 25% of Quillbot outputs scored ≤20% on Turnitin’s detector. The best path is always to create genuinely original work or do a thorough manual rewrite. So do try Quillbot’s rewriting services if you want to fix grammar or style, but never assume it will consistently fool Turnitin’s AI detection. That is the harsh truth.
