QuillBot
The most recognized paraphrasing tool available — and honestly, one of the only companies selling both a way to disguise AI writing and a way to detect it, in the same subscription.
What is QuillBot?
QuillBot, founded in 2017 and acquired by Course Hero (now Learneo) in 2021, is used by more than 50 million students, researchers, ESL writers, and professionals. Unlike a general-purpose AI chatbot, it doesn't generate content from a blank prompt — it needs text to work with, then rewrites, restructures, or refines it using a transformer-based model fine-tuned specifically for sentence-level rewriting. The core Paraphraser offers 9 to 10 distinct modes (Standard, Fluency, Formal, Academic, Creative, Expand, Shorten, and others, including a newer "Boomer Mode"), each producing a genuinely different rewrite rather than a marketing distinction — Standard covers most everyday rephrasing, while Academic and Formal shift register meaningfully. A synonym slider lets you control how aggressively the wording changes, and the tool bundles a grammar checker, summarizer, citation generator supporting more than 1,000 styles, and a plagiarism checker into the same subscription.
The honest thing worth understanding plainly: QuillBot sells both an AI Humanizer, designed to help AI-generated or heavily-paraphrased text read more naturally and evade detection, and an AI Detector, designed to catch exactly that kind of text — different products for different audiences, but worth knowing you're paying the same company for both sides of that equation. How well the Humanizer actually works is genuinely inconsistent depending on which test you look at: one detailed 2026 test found it dropped detection scores to near zero on several major detectors, while a separate independent poll found only a 42% average bypass rate across detectors, and a third found Turnitin specifically still flagged more than half the text as AI-assisted even after aggressive paraphrasing. Detectors are being actively retrained to recognize QuillBot's specific paraphrasing patterns, which is part of why results vary so much between tests and over time. It's also worth stating plainly: attempting to bypass academic AI-detection checks is very likely to violate a school's academic integrity policy, and no AI detector — QuillBot's included — is reliable enough to make a high-stakes judgment about someone's work. Separately, as of November 8, 2025, QuillBot began storing text inputs from desktop users to personalize the experience, a policy change worth knowing if you're working with sensitive material.
Feature details, the Humanizer/Detector tension, and efficacy test results are drawn from multiple independent 2026 reviews (ToolChase, EyeSift, Icon Polls, plisio.net, max-productive.ai), which report genuinely inconsistent bypass-rate findings across different tests — presented here honestly rather than favoring one figure. The November 2025 privacy policy change is corroborated by an independent review citing QuillBot's own notice.
Key features
9-10 mode paraphraser
Standard, Formal, Academic, Creative and more, with a synonym slider for fine control.
Grammar checker
Catches spelling, punctuation and grammar issues across 6 supported languages.
Citation Generator
Supports more than 1,000 citation styles for academic and research writing.
Plagiarism Checker
Scans up to 25,000 words a month for matched or copied content.
Summarizer
Condenses long passages into shorter summaries, with expanded limits on Premium.
Multilingual support
23 languages for paraphrasing, 50 for translation, with US/UK/CA/AU English dialect options.
Pricing
Free
- Paraphraser, grammar checker, AI detector included
- Limited summarizer word count
- No credit card required
Premium
- Unlimited paraphrasing, all modes, full Co-Writer/Flow workspace
- AI Humanizer and Plagiarism Checker included
- ~$99.95/year, about 31% cheaper than Grammarly's ~$144/year
Team / Education
- Scales Premium features across a group or school
- Contact QuillBot for volume pricing
- 3-day money-back guarantee applies to Premium purchases
Quarterly billing runs around $19.95, a middle option between monthly and annual. As of November 8, 2025, QuillBot stores desktop text inputs for personalization — review this policy directly if working with sensitive content. Prices reflect QuillBot's published pricing as verified through mid-2026.
Available models
Integrations & platforms
Pros, cons & best for
Pros
- Widely regarded as the most capable dedicated paraphrasing tool available
- Genuinely broad, well-integrated academic toolkit (citations, plagiarism, summarizer)
- Meaningfully cheaper than Grammarly for comparable breadth
Cons
- Aggressive paraphrasing can drift from the original meaning without review
- AI Humanizer bypass efficacy is genuinely inconsistent across independent tests
- Began storing desktop text inputs for personalization as of November 2025
Best for
- Students, researchers, and ESL writers needing to rephrase and cite sources
- Writers wanting a cheaper alternative to Grammarly with strong paraphrasing
- Not a tool for generating original content from a blank prompt
Take a look inside
Alternatives
For grammar-first checking or a different rewriting style instead:
Our verdict
QuillBot earns its reputation as the most trusted name in paraphrasing specifically because the core rewriting quality is genuinely good — the synonym slider and mode variety give real, usable control that basic synonym-swapping tools don't offer, and the bundled academic toolkit (citations, plagiarism checking, summarizing) makes it a legitimately useful one-stop workspace for students and researchers at a price that meaningfully undercuts Grammarly. The honest tension worth sitting with is that QuillBot sells both an AI Humanizer and an AI Detector, and independent tests disagree sharply on how well the Humanizer actually evades detection — treat any specific bypass claim skeptically, and remember that using it to get past academic integrity checks carries real institutional risk regardless of how well it tests on a given day. For its stated purpose — rewording text clearly while preserving meaning — it remains the strongest dedicated option in the category.
FAQ
Does QuillBot really sell both an AI Humanizer and an AI Detector?
Yes, both exist in the same product suite — the Humanizer aims to make AI-generated or paraphrased text read more naturally, while the Detector aims to catch exactly that kind of text. They serve different audiences, but it's worth understanding you're paying the same company either way.
Does QuillBot's AI Humanizer reliably bypass AI detection?
Results are genuinely inconsistent across independent tests — some found it dropped detection scores close to zero on several detectors, while others measured only a 42% average bypass rate, and Turnitin specifically still flagged more than half of tested text as AI-assisted. Treat any bypass claim skeptically.
Is using QuillBot to bypass academic AI detection against school policy?
Very likely, yes — attempting to bypass academic AI-detection checks is likely to violate most institutions' academic integrity policies, regardless of how effective the tool tests on a given day.
Is QuillBot free to use?
Yes, a free tier offers unlimited paraphrasing uses at 125 words each, plus grammar checking and AI detection, though Premium ($8.33-9.95/month) is required for unlimited-length paraphrasing, all modes, and the AI Humanizer.
Does QuillBot store my text?
As of November 8, 2025, QuillBot began storing text inputs from desktop users to personalize the experience — worth reviewing directly if you're working with sensitive or confidential content.
Is QuillBot cheaper than Grammarly?
Yes, on annual billing QuillBot Premium runs around $99.95/year compared to Grammarly's roughly $144/year, about 31% cheaper for comparable breadth of features.