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The September 2026 results are in: WriteHuman holds #1, and newcomer SupWriter debuts at #5.Read the full analysis →
HumanizerBench

Head to head · September 2026 cycle

StealthGPT vs SupWriter

SupWriter finished 7.7 points ahead of StealthGPT in the September 2026 cycle, 72.80 to 65.10, ranking #5 against #9 in a field of 14. SupWriter scored higher on 3 of 5 detectors and 6 of 7 writing categories. StealthGPT came out ahead on GPTZero (77.4 vs 21.0), readability (70.9 vs 45.7) and Originality.ai (89.5 vs 78.5). The bypass-rate gap, 79.6 to 80.3, sits inside both tools' 95% confidence intervals, so treat bypass as a draw.

65.10 /100
overall score
#9 /14
rank ▲ 3
+7.70
SupWriter leads →
Detectors
2 3
Categories
1 6
Components
1 4
72.80 /100
overall score
#5 /14
rank -
Last tested
Prompts
33
Methodology
v1.2.0

Score components

What the overall score is made of: bypass rate weighs 42%, meaning preservation 32%, readability 16%, consistency across categories 10%. Output-quality penalties come off the total. How scoring works →

Bypass rate CIs overlap SupWriter by 0.7
79.6 80.3
Meaning preservation SupWriter by 19.6
59.4 79.0
Readability StealthGPT by 25.2
70.9 45.7
Consistency SupWriter by 1.6
63.1 64.7
Penalties fewer is better SupWriter by 5.0
−5.0 None

CIs overlap marks a gap that sits inside both tools' published 95% confidence intervals for that component; it may not survive another cycle.

Detector by detector

Share of each tool's outputs that a detector classified as human-written. SupWriter took 3 of 5.

GPTZero StealthGPT by 56.4
77.4 21.0
Originality.ai StealthGPT by 11.0
89.5 78.5
Copyleaks SupWriter by 3.5
81.8 85.3
Winston AI SupWriter by 14.9
66.6 81.5
ZeroGPT SupWriter by 8.9
68.9 77.9

Writing categories

Category score per writing context: bypass credit only for real rewrites, blended with the category's own meaning preservation and readability. Small categories swing; the prompt count is shown on each row. How category scores work →

Academic Essay Application Essay Blog Post Business Email Marketing Copy Discussion Board News Article Academic Essay: StealthGPT 79.4 · SupWriter 79.7 Application Essay: StealthGPT 60.3 · SupWriter 67.1 Blog Post: StealthGPT 60.7 · SupWriter 78.4 Business Email: StealthGPT 42.7 · SupWriter 38.7 Marketing Copy: StealthGPT 73.1 · SupWriter 81.3 Discussion Board: StealthGPT 60.1 · SupWriter 78.0 News Article: StealthGPT 64.9 · SupWriter 81.1
StealthGPT SupWriter Outer ring = 100
Academic Essay 6 prompts SupWriter by 0.3
79.4 79.7
Application Essay 6 prompts SupWriter by 6.8
60.3 67.1
Blog Post 6 prompts SupWriter by 17.7
60.7 78.4
Business Email 3 prompts StealthGPT by 4.0
42.7 38.7
Marketing Copy 6 prompts SupWriter by 8.2
73.1 81.3
Discussion Board 3 prompts SupWriter by 17.9
60.1 78.0
News Article 3 prompts SupWriter by 16.2
64.9 81.1

Where each one wins

Every measure above that one tool won outright, largest margin first within each group.

StealthGPT

4 wins
  • Readability Score 70.9 vs 45.7
  • GPTZero Detector 77.4 vs 21.0
  • Originality.ai Detector 89.5 vs 78.5
  • Business Email Category 42.7 vs 38.7

SupWriter

13 wins
  • Penalties Score None vs −5.0
  • Meaning preservation Score 79.0 vs 59.4
  • Consistency Score 64.7 vs 63.1
  • Bypass rate Score 80.3 vs 79.6
  • Winston AI Detector 81.5 vs 66.6
  • ZeroGPT Detector 77.9 vs 68.9
  • Copyleaks Detector 85.3 vs 81.8
  • Discussion Board Category 78.0 vs 60.1
  • Blog Post Category 78.4 vs 60.7
  • News Article Category 81.1 vs 64.9
  • and 3 more

Questions people ask

Is StealthGPT better than SupWriter?

SupWriter finished 7.7 points ahead of StealthGPT in the September 2026 cycle, 72.80 to 65.10, ranking #5 against #9 in a field of 14. SupWriter scored higher on 3 of 5 detectors and 6 of 7 writing categories. Both tools ran the same 33 prompts, scored by the same 5 detectors, under methodology v1.2.0; every input, output and verdict is published.

Which bypasses AI detectors better, StealthGPT or SupWriter?

SupWriter posted the higher bypass rate, 80.3 vs 79.6, and scored higher on 3 of 5 detectors. StealthGPT led on GPTZero and Originality.ai; SupWriter led on Copyleaks, Winston AI and ZeroGPT. The overall bypass gap is inside both 95% confidence intervals, so it is not a reliable difference.

Do StealthGPT and SupWriter keep the original meaning?

SupWriter preserved meaning better, 79.0 vs 59.4 on our 0–100 similarity scale. On readability, StealthGPT rated higher, 70.9 vs 45.7. Penalties this cycle: StealthGPT −5.0, SupWriter None.