HumanToneHumanTone vs Undetectable AI vs QuillBot — Which Works Best?
By HumanTone Team
Three Tools, One Goal
You've generated text with ChatGPT and need it to sound human. Three tools come up constantly: HumanTone, Undetectable AI, and QuillBot. But they're actually quite different tools with different approaches.
Let's break down exactly how each one performs.
The Test Setup
We used the same 400-word GPT-4o passage about sustainable investing and ran it through each tool. We then checked the output against GPTZero, Originality.ai, and Copyleaks.
HumanTone
HumanTone is a dedicated AI text humanizer with 6 specialized modes.
What it does well:
- 93% average detection bypass rate
- Preserves original meaning with minimal drift
- 6 modes: Standard, Academic, Casual, Professional, Creative, Simple
- Completely free — no signup, no word limits
- Fast processing (under 3 seconds for 500 words)
Where it could improve:
- No browser extension yet
- Limited to English (more languages coming)
Output quality: The text reads naturally with varied sentence structure, appropriate contractions, and conversational flow. It doesn't just swap synonyms — it restructures sentences and adjusts tone.
Undetectable AI
Undetectable AI is a well-known commercial humanizer.
What it does well:
- 88% average detection bypass rate
- Clean, professional interface
- Multiple readability levels (High School, University, Doctorate)
- Built-in AI detection check
Where it falls short:
- Free tier is extremely limited (250 words/month)
- Premium starts at $9.99/month
- Occasionally over-paraphrases, changing meaning
- Slower processing than HumanTone
Output quality: Good overall, but we noticed it sometimes adds unnecessary filler phrases and occasionally shifts the meaning of technical passages.
QuillBot
QuillBot is primarily a paraphrasing tool — not a dedicated humanizer.
What it does well:
- Good general paraphrasing quality
- Multiple modes (Standard, Fluency, Formal, etc.)
- Browser extension and Word plugin
- Grammar checker included
Where it falls short:
- Only 62% detection bypass rate — it's not designed for this
- Free tier limited to 125 words at a time
- Premium: $9.95/month
- Doesn't target AI-specific patterns
Output quality: QuillBot produces well-paraphrased text, but it doesn't address the statistical patterns that AI detectors look for. You'll get a nicely reworded paragraph that still gets flagged as AI.
Side-by-Side Results
- Best bypass rate: HumanTone (93%) > Undetectable AI (88%) > QuillBot (62%)
- Best free tier: HumanTone (unlimited) > QuillBot (125 words) > Undetectable AI (250 words/month)
- Best for meaning preservation: HumanTone > QuillBot > Undetectable AI
- Best for academic writing: HumanTone (Academic mode) > Undetectable AI > QuillBot
- Most features overall: QuillBot (paraphrasing + grammar) > HumanTone > Undetectable AI
Our Verdict
For AI text humanization specifically, HumanTone is the best choice. It's purpose-built for the task, free, and achieves the highest bypass rates.
Undetectable AI is a reasonable paid alternative if you prefer its interface or need the built-in detection check.
QuillBot is great for general paraphrasing but shouldn't be your primary humanization tool. Use it alongside a dedicated humanizer, not instead of one.
If you need to make ChatGPT text sound human, start with HumanTone — it's free and takes about 3 seconds.
Frequently Asked Questions
Which tool bypasses AI detectors best?
In our testing, HumanTone achieved the highest average bypass rate at 93%, followed by Undetectable AI at 88%. QuillBot, being primarily a paraphraser, only achieved 62% because it does not specifically target AI detection patterns.
Is QuillBot an AI humanizer?
QuillBot is primarily a paraphrasing tool, not a dedicated AI humanizer. While it can help rewrite AI text, it does not specifically target the patterns that AI detectors look for, making it less effective for bypassing detection.
Which tool is cheapest?
HumanTone is completely free with no word limits. QuillBot costs $9.95/month for premium. Undetectable AI starts at $9.99/month. For budget-conscious users, HumanTone is the clear winner.