Head to head · September 2026 cycle
Grammarly vs SupWriter
SupWriter finished 12.4 points ahead of Grammarly in the September 2026 cycle, 72.80 to 60.35, ranking #5 against #12 in a field of 14. SupWriter scored higher on 5 of 5 detectors and 6 of 7 writing categories. Grammarly came out ahead on readability (66.1 vs 45.7), consistency across categories (78.7 vs 64.7) and meaning preservation (86.4 vs 79.0).
- Detectors
- 0 – 5
- Categories
- 1 – 6
- 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. SupWriter 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
4 wins- Readability Score 66.1 vs 45.7
- Consistency Score 78.7 vs 64.7
- Meaning preservation Score 86.4 vs 79.0
- Business Email Category 44.7 vs 38.7
SupWriter
13 wins- Bypass rate Score 80.3 vs 41.1
- Penalties Score None vs −3.0
- Winston AI Detector 81.5 vs 38.9
- Originality.ai Detector 78.5 vs 43.4
- Copyleaks Detector 85.3 vs 60.3
- ZeroGPT Detector 77.9 vs 58.0
- GPTZero Detector 21.0 vs 15.9
- Discussion Board Category 78.0 vs 44.5
- Marketing Copy Category 81.3 vs 56.5
- Blog Post Category 78.4 vs 58.9
- and 3 more
Questions people ask
Is Grammarly better than SupWriter?
SupWriter finished 12.4 points ahead of Grammarly in the September 2026 cycle, 72.80 to 60.35, ranking #5 against #12 in a field of 14. SupWriter scored higher on 5 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, Grammarly or SupWriter?
SupWriter posted the higher bypass rate, 80.3 vs 41.1, and scored higher on 5 of 5 detectors. SupWriter led on GPTZero, Originality.ai, Copyleaks, Winston AI and ZeroGPT.
Do Grammarly and SupWriter keep the original meaning?
Grammarly preserved meaning better, 86.4 vs 79.0 on our 0–100 similarity scale. On readability, Grammarly rated higher, 66.1 vs 45.7. Penalties this cycle: Grammarly −3.0, SupWriter None.