Head to head · September 2026 cycle
Grammarly vs StealthBypass
Grammarly finished 21.0 points ahead of StealthBypass in the September 2026 cycle, 60.35 to 39.38, ranking #12 against #13 in a field of 14. Grammarly scored higher on 0 of 5 detectors and 7 of 7 writing categories. StealthBypass came out ahead on GPTZero (69.3 vs 15.9), bypass rate (78.6 vs 41.1) and ZeroGPT (84.4 vs 58.0).
- Detectors
- 0 – 5
- Categories
- 7 – 0
- Components
- 3 – 2
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 →
Detector by detector
Share of each tool's outputs that a detector classified as human-written. StealthBypass took 5 of 5.
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 →
Where each one wins
Every measure above that one tool won outright, largest margin first within each group.
Grammarly
10 wins- Penalties Score −3.0 vs −23.0
- Meaning preservation Score 86.4 vs 39.5
- Readability Score 66.1 vs 54.1
- Marketing Copy Category 56.5 vs 18.9
- Blog Post Category 58.9 vs 28.2
- Application Essay Category 55.0 vs 24.5
- Academic Essay Category 69.5 vs 39.9
- News Article Category 62.8 vs 35.3
- Business Email Category 44.7 vs 26.0
- Discussion Board Category 44.5 vs 42.8
StealthBypass
7 wins- Bypass rate Score 78.6 vs 41.1
- Consistency Score 80.7 vs 78.7
- GPTZero Detector 69.3 vs 15.9
- ZeroGPT Detector 84.4 vs 58.0
- Winston AI Detector 56.3 vs 38.9
- Originality.ai Detector 58.5 vs 43.4
- Copyleaks Detector 65.1 vs 60.3
Questions people ask
Is Grammarly better than StealthBypass?
Grammarly finished 21.0 points ahead of StealthBypass in the September 2026 cycle, 60.35 to 39.38, ranking #12 against #13 in a field of 14. Grammarly scored higher on 0 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, Grammarly or StealthBypass?
StealthBypass posted the higher bypass rate, 78.6 vs 41.1, and scored higher on 5 of 5 detectors. StealthBypass led on GPTZero, Originality.ai, Copyleaks, Winston AI and ZeroGPT.
Do Grammarly and StealthBypass keep the original meaning?
Grammarly preserved meaning better, 86.4 vs 39.5 on our 0–100 similarity scale. On readability, Grammarly rated higher, 66.1 vs 54.1. Penalties this cycle: Grammarly −3.0, StealthBypass −23.0.