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

August 2026 prompt evidence

Each of these 33 prompts was written by a frontier model, then handed to all 12 ranked humanizers, and every rewrite was submitted to 5 commercial AI detectors. Every run was screen-recorded. Open a prompt to read the input, every tool's rewrite, each detector's verdict, and to watch the recording of that run.

33
Prompts
12
Tools ranked
396
Humanizer outputs
1980
Detector verdicts
How to read these scores

Each detector returns a human-likelihood on a common 0 to 1 scale, where 1 means it judged the text human-written and 0 means it flagged it as AI. On these pages a verdict counts as passed when that score is at least 0.50, the midpoint of the detector's own scale. That threshold exists only to draw the chips: the bypass rate on the leaderboard is the mean of each test's median score across the 5 detectors, a continuous number, so a tool's pass count and its bypass rate will not be the same figure.

Meaning is the input↔output embedding cosine and readability is a language-model writing-quality rating, both published per test in tests.json. Words is the output's length as a multiple of the input's; the scoring code penalizes ratios above 1.40 or below 0.60. Full definitions live in the methodology.

Prompt Category Written by Input words Passed Failed Open
01 Landing Copy Marketing Copy GPT-5.5 293 6 12
02 Argumentative Essay Academic Essay Gemini 3.5 Flash 382 4 11
03 Howto Blog Blog Post Claude Sonnet 5 405 1 11
04 Listicle Blog Blog Post Claude Sonnet 5 396 5 9
05 Product Desc Marketing Copy Claude Sonnet 5 199 8 9
06 Cover Letter Application Essay Gemini 3.5 Flash 359 2 12
07 Howto Blog Blog Post GPT-5.5 434 7 8
08 Howto Blog Blog Post Gemini 3.5 Flash 399 6 10
09 Landing Copy Marketing Copy Gemini 3.5 Flash 273 1 12
10 News Article News Article Gemini 3.5 Flash 373 7 9
11 Lit Review Academic Essay GPT-5.5 430 6 9
12 Lit Review Academic Essay Claude Sonnet 5 389 8 6
13 News Article News Article Claude Sonnet 5 407 3 9
14 Discussion Post Discussion Board GPT-5.5 255 4 9
15 News Article News Article GPT-5.5 426 6 9
16 Product Desc Marketing Copy Gemini 3.5 Flash 182 8 9
17 Landing Copy Marketing Copy Claude Sonnet 5 322 6 11
18 Discussion Post Discussion Board Claude Sonnet 5 260 6 9
19 Personal Statement Application Essay Gemini 3.5 Flash 337 8 8
20 Discussion Post Discussion Board Gemini 3.5 Flash 245 4 8
21 Business Email Business Email GPT-5.5 240 0 12
22 Listicle Blog Blog Post Gemini 3.5 Flash 426 8 8
23 Personal Statement Application Essay GPT-5.5 359 9 6
24 Business Email Business Email Gemini 3.5 Flash 236 1 12
25 Cover Letter Application Essay GPT-5.5 415 4 10
26 Personal Statement Application Essay Claude Sonnet 5 349 7 7
27 Argumentative Essay Academic Essay GPT-5.5 430 8 6
28 Business Email Business Email Claude Sonnet 5 273 0 12
29 Cover Letter Application Essay Claude Sonnet 5 402 1 11
30 Listicle Blog Blog Post GPT-5.5 433 6 10
31 Lit Review Academic Essay Gemini 3.5 Flash 405 10 10
32 Argumentative Essay Academic Essay Claude Sonnet 5 424 5 11
33 Product Desc Marketing Copy GPT-5.5 184 7 8

"Passed" counts the ranked tools whose rewrite of that prompt at least 4 of the 5 detectors scored as human-written (0.50 or above); "Failed" counts those flagged by at least one detector that scored them; "Hardest" is the single detector that flagged the most rewrites of that prompt.

Recordings

Every tool was run in a recorded sitting. Each recording opens here from the start; the outputs pages jump to the exact moment a prompt was run.

  • WriteHuman 11:56 · 33 prompts · Aug 1, 2026
  • Humanize AI Pro 10:58 · 33 prompts · Aug 2, 2026
  • Stealth Writer 9:00 · 33 prompts · Aug 1, 2026
  • HIX Bypass 9:21 · 33 prompts · Aug 1, 2026
  • Humbot 12:34 · 33 prompts · Aug 1, 2026
  • AI Humanize io 12:57 · 33 prompts · Aug 1, 2026
  • Phrasly 17:08 · 33 prompts · Aug 1, 2026
  • Undetectable.ai 14:46 · 33 prompts · Aug 1, 2026
  • Walter Writes 15:48 · 33 prompts · Aug 1, 2026
  • Super Humanizer 8:58 · 32 prompts · Aug 2, 2026
  • Grammarly 10:39 · 33 prompts · Aug 2, 2026
  • StealthGPT 16:24 · 33 prompts · Aug 1, 2026
  • NoteGPT not ranked this cycle 1:40 · 32 prompts · Aug 2, 2026

Session recording