AI Humanizer BenchmarkLeaderboard / Compare / Rephrasy vs UndetectedGPT
Head to head · November 2026 cycle
Rephrasy vs UndetectedGPT
On the November 2026 leaderboard, UndetectedGPT leads Rephrasy 76.03 to 72.97, a gap of 3.06 points. UndetectedGPT ranks #2 and Rephrasy ranks #3 out of 10 tools. UndetectedGPT scores higher on 2 of 7 detectors and in 4 of 7 writing categories. Rephrasy is ahead on bypass rate (80.0% vs 70.7%), consistency (80.7 vs 76.5) and GPTZero (82.6 vs 61.2). The two tools' 95% confidence intervals for bypass rate overlap, so that difference is not statistically clear.
- Detectors
- 5 – 2
- Categories
- 3 – 4
- Components
- 2 – 3
- Last tested
- Prompts
- 33
- Methodology
- v1.2.0
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
Overlapping CIs means the two tools' 95% confidence intervals for bypass rate overlap, so the bypass difference is not statistically clear.
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. Rephrasy scores higher on 5 of 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.
Rephrasy
10 wins- Bypass rate Score80.0 vs 70.7
- Consistency Score80.7 vs 76.5
- GPTZero Detector82.6 vs 61.2
- Originality.ai Detector28.1 vs 7.7
- Copyleaks Detector87.9 vs 75.8
- Pangram Detector17.2 vs 6.2
- ZeroGPT Detector75.5 vs 71.3
- Business email Category70.2 vs 60.0
- Blog post Category79.0 vs 69.3
- Discussion board Category84.7 vs 83.5
UndetectedGPT
9 wins- Meaning preservation Score79.0 vs 69.6
- Readability Score83.7 vs 75.3
- Penalties ScoreNone vs −3.0
- QuillBot Detector92.3 vs 83.9
- Grammarly Detector93.1 vs 86.5
- News article Category87.4 vs 78.7
- Application essay Category67.7 vs 61.4
- Academic essay Category82.2 vs 78.4
- Marketing copy Category83.5 vs 82.3
Questions people ask
Is Rephrasy better than UndetectedGPT?
On the November 2026 leaderboard, UndetectedGPT has an overall score of 76.03 and Rephrasy has 72.97, a gap of 3.06 points. UndetectedGPT ranks #2 and Rephrasy ranks #3 out of 10 tools. UndetectedGPT scores higher on 2 of 7 detectors and in 4 of 7 writing categories. Both tools rewrote the same 33 prompts, the same 7 detectors checked every output, and scoring followed methodology v1.2.0. All inputs, outputs and detector verdicts are public.
Which bypasses AI detectors better, Rephrasy or UndetectedGPT?
Rephrasy has the higher bypass rate, 80.0% vs 70.7% for UndetectedGPT. Rephrasy scores higher on GPTZero, Originality.ai, Copyleaks, Pangram and ZeroGPT. UndetectedGPT scores higher on QuillBot and Grammarly. The two tools' 95% confidence intervals for bypass rate overlap, so the difference is not statistically clear.
Do Rephrasy 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 79.0 and Rephrasy scores 69.6. On readability, UndetectedGPT scores higher, 83.7 vs 75.3. This cycle, Rephrasy lost 3.0 points to penalties and UndetectedGPT had no penalties.