QuillBot AI Humanizer Review: Best Free Option? (2025)
Is QuillBot the best free AI humanizer? We tested QuillBot's paraphrasing modes as an AI humanizer, including its ability to bypass GPTZero and Grammarly.
Pros
- Generous free tier (125 words per paraphrase)
- 7 writing modes for different styles
- Chrome extension for in-browser humanizing
- Built-in grammar checker and summarizer
- Very natural, high-quality output
Cons
- 125-word limit on free plan is restrictive
- Not specifically designed for AI detection bypass
- Turnitin bypass rate is lower than dedicated tools
- Paraphrasing AI in a word processor UI
QuillBot is one of the most popular AI writing tools, and its paraphrasing engine works surprisingly well as an AI humanizer. But how does it stack up against dedicated humanizer tools?
QuillBot as an AI Humanizer: What You Need to Know
QuillBot was designed as a paraphraser, not specifically as an AI humanizer. However, because it rewrites text in natural, varied language, it happens to humanize AI-generated content quite effectively.
QuillBot's Writing Modes
QuillBot offers 7 modes (free users get 2):
- Standard — Balanced rewriting (free)
- Fluency — Focuses on grammar and natural flow (free)
- Formal — Professional tone (premium)
- Simple — Shorter, simpler sentences (premium)
- Creative — More inventive rewrites (premium)
- Expand — Longer, more detailed output (premium)
- Shorten — Condensed output (premium)
For AI humanizing purposes, Fluency mode produces the most natural-sounding results.
AI Detection Bypass Results
We tested QuillBot's output (Fluency mode) against major detectors:
| AI Detector | Before QuillBot | After QuillBot |
|---|---|---|
| GPTZero | 96% AI | 31% AI |
| Grammarly | 89% AI | 29% AI |
| Originality.ai | 98% AI | 44% AI |
| Turnitin | 93% AI | 58% AI |
GPTZero and Grammarly bypass is solid. Turnitin bypass is notably weaker than Undetectable AI.
Output Quality
QuillBot's biggest strength is output quality. The rewrites read naturally and fluently, preserve meaning accurately, maintain appropriate tone, and rarely produce awkward phrasing.
For general content humanizing, QuillBot's quality is actually competitive with premium tools.
Free Tier: Is It Enough?
QuillBot's free tier gives you:
- 125 words per paraphrase
- Access to Standard and Fluency modes
- Word flipper for synonym suggestions
For short content or casual use, this is sufficient. For blog posts or longer content, you'll hit the limit quickly.
QuillBot Premium Pricing (2025)
- Monthly: $19.95/month
- Semi-Annual: $13.33/month
- Annual: $9.95/month
Premium unlocks all 7 modes, removes the word limit, and adds advanced features.
QuillBot vs. Undetectable AI
| Feature | QuillBot (Free) | Undetectable AI |
|---|---|---|
| Word limit | 125/req | ~250 free |
| Output quality | Excellent | Very Good |
| GPTZero bypass | Good | Excellent |
| Turnitin bypass | Moderate | Excellent |
| Price (paid) | $9.95/mo | $9.99/mo |
Final Verdict: 4.7/5
QuillBot is the best free AI humanizer for everyday use. The output quality is excellent, the free tier is usable, and the Chrome extension makes it incredibly convenient.
It falls short of dedicated tools like Undetectable AI for Turnitin bypass, but for most users, QuillBot is more than sufficient — especially at no cost.