AI Humanizer BenchmarkLeaderboard / Compare / StealthGPT vs UndetectedGPT
Head to head · October 2026 cycle
StealthGPT vs UndetectedGPT
On the October 2026 leaderboard, UndetectedGPT leads StealthGPT 88.12 to 64.52, a gap of 23.60 points. UndetectedGPT ranks #1 and StealthGPT ranks #9 out of 11 tools. UndetectedGPT scores higher on all 7 detectors and in all 7 writing categories.
- Detectors
- 0 – 7
- Categories
- 0 – 7
- Components
- 0 – 5
- 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. UndetectedGPT 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
0 winsNot ahead on any measure this cycle.
UndetectedGPT
19 wins- Bypass rate Score96.0 vs 62.8
- Consistency Score96.6 vs 75.9
- Meaning preservation Score77.4 vs 67.7
- Penalties ScoreNone vs −4.0
- Readability Score83.6 vs 80.6
- Originality.ai Detector96.7 vs 62.7
- GPTZero Detector72.0 vs 41.5
- QuillBot Detector91.0 vs 61.3
- Winston AI Detector84.4 vs 55.3
- Grammarly Detector96.8 vs 69.0
- ZeroGPT Detector92.3 vs 67.4
- Copyleaks Detector78.8 vs 60.6
- Application essay Category88.1 vs 51.2
- Business email Category84.3 vs 59.5
- Discussion board Category91.7 vs 69.6
- News article Category92.4 vs 70.8
- Blog post Category87.9 vs 70.1
- Academic essay Category90.5 vs 78.3
- Marketing copy Category84.0 vs 77.3
Questions people ask
Is StealthGPT better than UndetectedGPT?
On the October 2026 leaderboard, UndetectedGPT has an overall score of 88.12 and StealthGPT has 64.52, a gap of 23.60 points. UndetectedGPT ranks #1 and StealthGPT ranks #9 out of 11 tools. UndetectedGPT 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 UndetectedGPT?
UndetectedGPT has the higher bypass rate, 96.0% vs 62.8% for StealthGPT. It scores higher on all 7 detectors. The two tools' 95% confidence intervals for bypass rate do not overlap.
Do StealthGPT and UndetectedGPT keep the original meaning?
Meaning preservation measures how close each output stays to its input, using embedding similarity on a 0–100 scale. UndetectedGPT scores 77.4 and StealthGPT scores 67.7. On readability, UndetectedGPT scores higher, 83.6 vs 80.6. This cycle, StealthGPT lost 4.0 points to penalties and UndetectedGPT had no penalties.