AI Humanizer BenchmarkLeaderboard / Compare / StealthGPT vs Undetectable AI
Head to head · October 2026 cycle
StealthGPT vs Undetectable AI
On the October 2026 leaderboard, StealthGPT leads Undetectable AI 64.52 to 33.60, a gap of 30.92 points. StealthGPT ranks #9 and Undetectable AI ranks #11 out of 11 tools. StealthGPT scores higher on all 7 detectors and in all 7 writing categories. Undetectable AI is ahead on consistency (97.8 vs 75.9) and meaning preservation (72.9 vs 67.7).
- Detectors
- 7 – 0
- Categories
- 7 – 0
- Components
- 3 – 2
- Last tested
- Prompts
- 33
- Methodology
- v1.1.0
Score components
The overall score weights bypass rate at 42%, meaning preservation at 32%, readability at 16% and consistency across writing categories at 10%. Penalties for output-quality failures are then subtracted. Full scoring formula
Detector by detector
Each figure is one detector's average human-likelihood score across all of a tool's outputs, on a 0–100 scale. Higher means more human. StealthGPT scores higher on all 7 detectors.
Writing categories
Each category score applies the overall-score weights to that category's prompts only. Bypass, meaning preservation and readability are averaged within the category, and the tool's overall consistency score is added. Penalties are not subtracted. Categories with few prompts give less reliable scores, so each row shows its prompt count.
Where each one wins
Measures where one tool is ahead of the other. Ties are left out. Score components come first, then detectors, then categories, with the largest gap first in each group.
StealthGPT
17 wins- Bypass rate Score62.8 vs 1.8
- Penalties Score−4.0 vs −12.0
- Readability Score80.6 vs 73.2
- Copyleaks Detector60.6 vs 1.5
- Originality.ai Detector62.7 vs 3.8
- Winston AI Detector55.3 vs 3.0
- Grammarly Detector69.0 vs 20.6
- QuillBot Detector61.3 vs 14.5
- ZeroGPT Detector67.4 vs 34.5
- GPTZero Detector41.5 vs 12.0
- Academic essay Category78.3 vs 39.6
- Marketing copy Category77.3 vs 43.9
- Discussion board Category69.6 vs 39.0
- News article Category70.8 vs 51.7
- Blog post Category70.1 vs 53.0
- Business email Category59.5 vs 49.0
- Application essay Category51.2 vs 44.5
Undetectable AI
2 wins- Consistency Score97.8 vs 75.9
- Meaning preservation Score72.9 vs 67.7
Questions people ask
Is StealthGPT better than Undetectable AI?
On the October 2026 leaderboard, StealthGPT has an overall score of 64.52 and Undetectable AI has 33.60, a gap of 30.92 points. StealthGPT ranks #9 and Undetectable AI ranks #11 out of 11 tools. StealthGPT scores higher on all 7 detectors and in all 7 writing categories. Both tools rewrote the same 33 prompts, the same 7 detectors checked every output, and scoring followed methodology v1.1.0. All inputs, outputs and detector verdicts are public.
Which bypasses AI detectors better, StealthGPT or Undetectable AI?
StealthGPT has the higher bypass rate, 62.8% vs 1.8% for Undetectable AI. It scores higher on all 7 detectors. The two tools' 95% confidence intervals for bypass rate do not overlap.
Do StealthGPT and Undetectable AI keep the original meaning?
Meaning preservation measures how close each output stays to its input, using embedding similarity on a 0–100 scale. Undetectable AI scores 72.9 and StealthGPT scores 67.7. On readability, StealthGPT scores higher, 80.6 vs 73.2. This cycle, StealthGPT lost 4.0 points to penalties and Undetectable AI lost 12.0 points to penalties.