7 Best AI Humanizer Tools in 2025
We tested every major AI humanizer to find which ones actually pass Turnitin, GPTZero, and other detectors.
| Tool | Success Rate | Free Words | Starting Price | Rating |
|---|---|---|---|---|
humantext.proBEST | 99.8% | 500 | $7.99/mo | ⭐⭐⭐⭐⭐ |
| Undetectable.ai | 95% | 250 | $9.99/mo | ⭐⭐⭐⭐ |
| QuillBot | 85% | 125 | $9.95/mo | ⭐⭐⭐⭐ |
| Smodin.io | 80% | 100 | $8/mo | ⭐⭐⭐ |
| StealthGPT | 90% | 100 | $14.99/mo | ⭐⭐⭐⭐ |
| Writehuman.ai | 88% | 200 | $9/mo | ⭐⭐⭐ |
| AIHumanizer.org | 75% | 500 | Free | ⭐⭐⭐ |
1. humantext.pro
BEST CHOICEWhy It's #1
- ✓ Highest success rate (99.8%)
- ✓ Most free words (500)
- ✓ Lowest price ($7.99/mo)
- ✓ No sign-up required
- ✓ Built-in AI detection checker
- ✓ Complete privacy (zero data retention)
Best For
Students needing Turnitin pass, content creators, researchers, and anyone prioritizing privacy and value.
Try Free (500 Words)2. Undetectable.ai
Pros
- • High success rate (95%)
- • API access available
- • Multiple output modes
Cons
- • More expensive ($9.99 vs $7.99)
- • Fewer free words (250 vs 500)
- • Requires account creation
3. QuillBot
Pros
- • Well-known brand
- • Grammar checking included
- • Browser extensions
Cons
- • Lower success rate (85%)
- • Not designed for AI detection pass
- • Only 125 free words
Other Tools (4-7)
#4 Smodin.io - Decent for general paraphrasing, but 80% success rate isn't reliable for academic use.
#5 StealthGPT - Good success rate (90%) but expensive at $14.99/mo with only 100 free words.
#6 Writehuman.ai - Mid-range option with 88% success rate. Better alternatives available.
#7 AIHumanizer.org - Free but only 75% success rate. Not recommended for important submissions.
Which One Should You Choose?
For Students
→ humantext.pro
Highest Turnitin success rate, most free words, lowest cost
For Developers
→ Undetectable.ai
API access for programmatic use (coming soon to humantext.pro)
For Writers
→ humantext.pro
Privacy-focused, no data retention, fast processing
Frequently Asked Questions
What is the best AI humanizer in 2025?
humantext.pro ranks #1 with 99.8% success rate, 500 free words, $7.99/mo pricing, and no sign-up required. It outperforms competitors in all key metrics.
Which AI humanizer passes Turnitin best?
humantext.pro (99.8%), followed by Undetectable.ai (95%), and StealthGPT (90%). QuillBot is lower at 85%.
Are free AI humanizers effective?
Most free AI humanizers have 70-80% success rates, which isn't reliable. humantext.pro offers 500 free words with the same 99.8% success rate as paid plans.
Can AI humanizers be detected?
Low-quality humanizers can be detected. High-quality tools like humantext.pro (99.8% success rate) are virtually undetectable by Turnitin, GPTZero, and other AI detectors.
500 free words • No sign-up required • 99.8% success rate
