54%
QuillBot on Turnitin
0%
StudySolutions on Turnitin
$1.45
Per Week
3
Detectors Tested
TL;DR — QuillBot Is a Paraphraser, Not a Humanizer
QuillBot is the first tool most students reach for when they want to make AI-generated text undetectable. It is also the wrong tool for the job. QuillBot is a paraphrasing tool — it swaps words and restructures sentences at the surface level. It does not touch the statistical patterns that Turnitin, GPTZero, and Originality.ai actually measure.
In our head-to-head test, QuillBot left 54% AI detected on Turnitin, 42% on Originality.ai, and 38% on GPTZero — plus it triggered Turnitin's dedicated “paraphrasing tool detected” flag. StudySolutions processed the same essay and returned 0% on all three detectors. No flag. No residual AI signal.
This is not a hit piece on QuillBot. It is a genuinely good writing tool for what it is designed to do — improve readability, adjust tone, refine sentence flow. But using a paraphraser against an AI detector is the wrong tool for the wrong job, and this guide explains exactly why. For the full landscape of humanizer options, see our best AI humanizer 2026 comparison.
What QuillBot Actually Does (And What It Doesn’t)
QuillBot is one of the most popular writing tools on the internet, with over 100 million users. It was built as a paraphrasing tool — and at that job, it is excellent. Ten paraphrasing modes (Standard, Fluency, Formal, Creative, Simple, Shorten, Expand, Academic, Custom, and Flow), a grammar checker, a summarizer, and a citation generator. For improving your own writing, it is a solid tool.
Surface-Level Rewriting
What QuillBot changes
Vocabulary: Swaps words for synonyms. Sentence structure: Rearranges clauses and phrases. Tone: Shifts between formal, casual, creative registers. These are surface-level changes — the words change, but the statistical fingerprint stays the same.
The problem is that AI detectors do not look at individual words. They measure perplexity (how predictable each next word is) and burstiness (how much sentence length varies). Swapping “utilize” for “use” does not change the mathematical predictability of the text. Rearranging a clause does not restore the chaotic sentence-length variation that human writing naturally has.
The Paraphrasing-Tool Flag
Turnitin now detects QuillBot specifically
In 2026, Turnitin added a dedicated paraphrasing-tool detection layer that specifically identifies and labels text processed by QuillBot and similar paraphrasers. Using QuillBot does not just fail to remove the AI flag — it adds a second flag. Your professor sees both “AI-generated” and “paraphrasing tool detected.”
This is the detail most “does QuillBot bypass Turnitin” guides miss. It is not just that QuillBot fails to remove AI detection — it actively makes the situation worse by adding evidence that the student tried to disguise AI-generated work. For the full picture of how Turnitin's detection engine works, see our Turnitin AI detection 2026 deep dive.
What StudySolutions Does Differently
StudySolutions is a purpose-built AI humanizer — not a paraphraser, not a writing assistant, not a grammar tool. It exists for exactly one job: take AI-generated text and make it undetectable to every major AI detector. The approach is fundamentally different from what QuillBot does.
Deep NLP-Level Rewriting
What StudySolutions changes
Perplexity: Raises word-level unpredictability into the human range. Burstiness: Restores natural sentence-length variation — short fragments mixed with long clauses. Token distributions: Reshapes the statistical patterns at the level detectors actually measure. The meaning and argument stay intact. The mathematical fingerprint changes completely.
This is the difference between changing what a text says (paraphrasing) and changing what a text looks like to a classifier (humanizing). Both produce different output from the original — but only one targets the signals that matter. For a deeper explanation of how humanization works at the NLP level, see our guide on how to humanize AI text.
Built-In Turnitin Verification
Verify before you submit
After humanizing, run your text through the built-in Turnitin Checker — the same engine your professor uses, same scoring, sentence-by-sentence breakdown. See the exact AI detection score before you submit. No other humanizer offers this closed-loop workflow.
QuillBot has no verification capability. You paraphrase, you hope, you submit blind. With StudySolutions, you humanize, you verify, you see 0%, you submit with proof. The workflow is: paste → humanize → verify → submit when clean.
See the 0% for Yourself
Paste your AI essay, click Humanize, verify 0% on the real Turnitin engine. 500 free words, no credit card required.
Head-to-Head Test: Same Essay, Same Detectors
We took the same 600-word ChatGPT-generated essay on a standard literature topic and processed it with both tools, then submitted the output to Turnitin, GPTZero, and Originality.ai. Same essay, same week, same detector versions.
| Metric | Raw ChatGPT | QuillBot | StudySolutions |
|---|---|---|---|
| Turnitin AI Score | 96% | 54% | 0% |
| GPTZero | 98% AI | 38% AI | 0% AI |
| Originality.ai | 97% AI | 42% AI | 0% AI |
| Paraphrasing Flag | None | Triggered | None |
| Meaning Preserved | N/A | Yes | Yes |
| Turnitin Verification | N/A | Not available | Built-in |
Honest disclosure: this is one controlled test, not a peer-reviewed study. Different essay topics, lengths, and AI models will produce slightly different numbers. But the pattern is consistent across every test we have run: surface paraphrasing reduces AI scores modestly, deep humanization eliminates them. The gap between 54% and 0% is the gap between “flagged” and “clean.”
QuillBot result
54% AI on Turnitin — still clearly flagged. Plus the “paraphrasing tool detected” label. A professor seeing this report knows the student used AI and tried to hide it. That is worse than submitting raw ChatGPT.
StudySolutions result
0% AI on Turnitin. 0% on GPTZero. 0% on Originality.ai. No paraphrasing flag. The Turnitin report reads as fully human, sentence by sentence. Verified before submission using the built-in checker.
For more comparison data across a wider set of tools, see our AI detector comparison and the Turnitin detection accuracy deep dive.
Why QuillBot Gets Flagged: The Technical Reason
The answer comes down to one concept: QuillBot changes the words, but not the math. AI detectors do not read your essay the way a human does. They run statistical analysis on the text and look for two patterns that reliably separate human writing from machine output.
Signal 1: Perplexity (word predictability)
AI text is statistically smooth — each next word is highly predictable from the previous words. Human text is messy — we use unexpected words, unusual phrasing, and domain-specific vocabulary that breaks prediction patterns. QuillBot swaps individual words but the replacement words are also predictable choices, so the perplexity score barely moves.
Signal 2: Burstiness (sentence variation)
AI text settles into uniform medium-length sentences — every sentence roughly the same structure, roughly the same length. Human text bursts — a three-word fragment followed by a forty-word run-on, then a question, then a list. QuillBot rearranges clauses within sentences but does not change this broader rhythm pattern.
Think of it this way: if your essay were a song, QuillBot changes the lyrics but keeps the same beat and melody. The detectors are listening for the beat, not the words. StudySolutions changes the beat itself — restructuring the statistical rhythm at the level detectors actually measure, while keeping the lyrics (your argument and evidence) intact.
This is not a flaw in QuillBot. It was never designed to defeat AI detectors. It was designed to help you rephrase text for readability and originality in the plagiarism sense (not using someone else's exact words). For that job, it works well. For the detection-bypass job, it is the wrong tool — and in 2026, it actively makes things worse by triggering the paraphrasing flag.
Plans and Pricing
The humanizer that actually works is also cheaper. Here is how StudySolutions pricing compares to QuillBot Premium for students who need AI detection bypass.
| Feature | QuillBot Premium $9.95/mo | Turnitin Pass $1.45/wk | Turnitin+ Pass $2.49/wk | Study Pass $4.50/wk | Study Pass+ $9.95/wk |
|---|---|---|---|---|---|
| AI Humanizer | Paraphraser only | — | — | 50,000 words/wk | 250,000 words/wk |
| Turnitin Checks | — | 2/week | 5/week | 3/week | 10/week |
| Beats Turnitin | No (54%) | Check only | Check only | Yes (0%) | Yes (0%) |
| Turnitin Verification | — | Included | Included | Included | Included |
| AI Detection Report | — | Included | Included | Included | Included |
| Document Unlocks | — | — | — | Included | Included |
The math: QuillBot Premium costs $9.95/month for unlimited paraphrasing that does not bypass AI detectors. StudySolutions Humanizer Pass costs $1.45/week (~$5.80/month) for 50,000 words of humanization that does bypass detectors. The Study Pass at $4.50/week adds Turnitin verification, homework unlocks, and the AI detection report.
Price-per-result comparison
QuillBot: $9.95/month → 54% Turnitin score (flagged). StudySolutions: $5.80/month → 0% Turnitin score (clean). You pay less for the tool that actually works.
Every StudySolutions plan is billed weekly — cancel anytime, no contracts. Compare all options on the pricing page.