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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

Penlify vs Stealth Writer

Stealth Writer finished 38.8 points ahead of Penlify in the September 2026 cycle, 75.39 to 36.57, ranking #2 against #14 in a field of 14. Stealth Writer scored higher on 5 of 5 detectors and 7 of 7 writing categories. Penlify came out ahead on readability (71.8 vs 47.2) and consistency across categories (100.0 vs 81.4).

36.57 /100
overall score
#14 /14
rank -
+38.82
Stealth Writer leads →
Detectors
0 5
Categories
0 7
Components
2 3
75.39 /100
overall score
#2 /14
rank ▲ 1
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 Stealth Writer by 86.4
0.0 86.4
Meaning preservation Stealth Writer by 13.6
62.7 76.3
Readability Penlify by 24.6
71.8 47.2
Consistency Penlify by 18.6
100.0 81.4
Penalties fewer is better Stealth Writer by 4.0
−5.0 −1.0

Detector by detector

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

GPTZero Stealth Writer by 33.9
0.0 33.9
Originality.ai Stealth Writer by 97.4
0.0 97.4
Copyleaks Stealth Writer by 81.8
0.0 81.8
Winston AI Stealth Writer by 79.9
0.4 80.3
ZeroGPT Stealth Writer by 38.1
43.0 81.1

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: Penlify 27.0 · Stealth Writer 83.7 Application Essay: Penlify 35.9 · Stealth Writer 62.5 Blog Post: Penlify 37.3 · Stealth Writer 80.1 Business Email: Penlify 39.9 · Stealth Writer 54.3 Marketing Copy: Penlify 38.8 · Stealth Writer 82.0 Discussion Board: Penlify 32.1 · Stealth Writer 84.0 News Article: Penlify 36.6 · Stealth Writer 66.1
Penlify Stealth Writer Outer ring = 100
Academic Essay 6 prompts Stealth Writer by 56.7
27.0 83.7
Application Essay 6 prompts Stealth Writer by 26.6
35.9 62.5
Blog Post 6 prompts Stealth Writer by 42.9
37.3 80.1
Business Email 3 prompts Stealth Writer by 14.4
39.9 54.3
Marketing Copy 6 prompts Stealth Writer by 43.1
38.8 82.0
Discussion Board 3 prompts Stealth Writer by 51.9
32.1 84.0
News Article 3 prompts Stealth Writer by 29.6
36.6 66.1

Where each one wins

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

Penlify

2 wins
  • Readability Score 71.8 vs 47.2
  • Consistency Score 100.0 vs 81.4

Stealth Writer

15 wins
  • Bypass rate Score 86.4 vs 0.0
  • Penalties Score −1.0 vs −5.0
  • Meaning preservation Score 76.3 vs 62.7
  • Originality.ai Detector 97.4 vs 0.0
  • Copyleaks Detector 81.8 vs 0.0
  • Winston AI Detector 80.3 vs 0.4
  • ZeroGPT Detector 81.1 vs 43.0
  • GPTZero Detector 33.9 vs 0.0
  • Academic Essay Category 83.7 vs 27.0
  • Discussion Board Category 84.0 vs 32.1
  • and 5 more

Questions people ask

Is Penlify better than Stealth Writer?

Stealth Writer finished 38.8 points ahead of Penlify in the September 2026 cycle, 75.39 to 36.57, ranking #2 against #14 in a field of 14. Stealth Writer scored higher on 5 of 5 detectors and 7 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, Penlify or Stealth Writer?

Stealth Writer posted the higher bypass rate, 86.4 vs 0.0, and scored higher on 5 of 5 detectors. Stealth Writer led on GPTZero, Originality.ai, Copyleaks, Winston AI and ZeroGPT.

Do Penlify and Stealth Writer keep the original meaning?

Stealth Writer preserved meaning better, 76.3 vs 62.7 on our 0–100 similarity scale. On readability, Penlify rated higher, 71.8 vs 47.2. Penalties this cycle: Penlify −5.0, Stealth Writer −1.0.