HumanizerEval

Leaderboard / Archive / September 2026

Frozen at publication

Review archive: September 2026

In the September 2026 HumanizerEval review, StealthGPT Super ranked first of 10 humanizers across 5 detectors. This was the first published comparison review.

Run details

Review
September 2026
Run date
September 30, 2026 (America/New_York)
Methodology version
v1.0
Scoring script version
v1.0
Prompt set version
None; production sample
Humanizers
StealthGPT Super; WriteHuman; Grubby; Rephrasy; Undetectable.ai; RewriteAI; HIX Bypass; Humbot; BypassGPT; Ryne
Detectors
Pangram 4.0; GPTZero 2026-09-13-base; Originality.ai turbo; ZeroGPT default; Winston AI 5.0
Sample
50 English texts, 300 to 995 words, mean 596; same source texts for every humanizer
Detector access
Vendor APIs; the same output sent to every detector
Report ID
2026-09-30-humanizer-comparison
SHA-256 of scores.csv
e78de0985b8c057da00293a0606548066299508e55bcd2a708e62526549b0f25

Results

AI humanizer comparison, September 2026. Sorted by the mean strict-bypass rate across the 5 detectors. Every tool rewrote the same 50 texts, and every output went to every detector.
#HumanizerPangramGPTZeroOriginality.aiZeroGPTWinston AI
1StealthGPTPassed all 5 detectors on 46 of 5096.8%92%98%98%98%98%83.5%1.04
2WriteHumanPassed all 5 detectors on 32 of 4992.7%65%100%98%100%100%58.7%1.02
3GrubbyPassed all 5 detectors on 18 of 5085.6%36%94%98%100%100%77.5%1.11
4RephrasyPassed all 5 detectors on 20 of 5084.0%46%88%86%100%100%54.5%1.13
5Undetectable.aiPassed all 5 detectors on 15 of 5084.0%32%96%94%100%98%56.5%1.21
6RewriteAIPassed all 5 detectors on 13 of 5077.2%28%86%88%88%96%72.0%1.09
7HIX BypassPassed all 5 detectors on 1 of 5066.4%2%68%64%100%98%46.5%1.11
8HumbotPassed all 5 detectors on 0 of 5066.4%0%62%70%100%100%47.5%1.12
9BypassGPTPassed all 5 detectors on 0 of 5064.4%0%56%66%100%100%49.0%1.12
10RynePassed all 5 detectors on 0 of 5023.6%22%8%0%62%26%79.0%1.07

Each column counts how many of the 50 texts that detector called human-written. Rank is the average of the five columns. WriteHuman returned 49 of 50 outputs, so its rates are out of 49. Full methodology.

  • Pangram
  • GPTZero
  • Originality.ai
  • ZeroGPT
  • Winston AI
Strict-bypass rate by detector for each humanizer in the September 2026 review.0%25%50%75%100%StealthGPTStealthGPT Super, Pangram: 92%StealthGPT Super, GPTZero: 98%StealthGPT Super, Originality.ai: 98%StealthGPT Super, ZeroGPT: 98%StealthGPT Super, Winston AI: 98%WriteHumanWriteHuman, Pangram: 65%WriteHuman, GPTZero: 100%WriteHuman, Originality.ai: 98%WriteHuman, ZeroGPT: 100%WriteHuman, Winston AI: 100%GrubbyGrubby, Pangram: 36%Grubby, GPTZero: 94%Grubby, Originality.ai: 98%Grubby, ZeroGPT: 100%Grubby, Winston AI: 100%RephrasyRephrasy, Pangram: 46%Rephrasy, GPTZero: 88%Rephrasy, Originality.ai: 86%Rephrasy, ZeroGPT: 100%Rephrasy, Winston AI: 100%Undetectable.aiUndetectable.ai, Pangram: 32%Undetectable.ai, GPTZero: 96%Undetectable.ai, Originality.ai: 94%Undetectable.ai, ZeroGPT: 100%Undetectable.ai, Winston AI: 98%RewriteAIRewriteAI, Pangram: 28%RewriteAI, GPTZero: 86%RewriteAI, Originality.ai: 88%RewriteAI, ZeroGPT: 88%RewriteAI, Winston AI: 96%HIX BypassHIX Bypass, Pangram: 2%HIX Bypass, GPTZero: 68%HIX Bypass, Originality.ai: 64%HIX Bypass, ZeroGPT: 100%HIX Bypass, Winston AI: 98%HumbotHumbot, Pangram: 0%Humbot, GPTZero: 62%Humbot, Originality.ai: 70%Humbot, ZeroGPT: 100%Humbot, Winston AI: 100%BypassGPTBypassGPT, Pangram: 0%BypassGPT, GPTZero: 56%BypassGPT, Originality.ai: 66%BypassGPT, ZeroGPT: 100%BypassGPT, Winston AI: 100%RyneRyne, Pangram: 22%Ryne, GPTZero: 8%Ryne, Originality.ai: 0%Ryne, ZeroGPT: 62%Ryne, Winston AI: 26%Strict-bypass rate, % of texts

Pangram 4.0

Pangram 4.0 results, September 2026. Same 50 texts for every tool.
HumanizerStrict bypassTexts passedMean human scoreMedian human score
StealthGPT Super92%46 of 5088.9%100%
WriteHuman65%32 of 4963.6%91.39%
Rephrasy46%23 of 5047.2%34.53%
Grubby36%18 of 5039.8%10.69%
Undetectable.ai32%16 of 5031.4%8.21%
RewriteAI28%14 of 5029.6%0%
Ryne22%11 of 5025.9%12.58%
HIX Bypass2%1 of 501.8%0%
Humbot0%0 of 501.4%0%
BypassGPT0%0 of 501.4%0%

GPTZero 2026-09-13-base

GPTZero 2026-09-13-base results, September 2026. Same 50 texts for every tool.
HumanizerStrict bypassTexts passedMean human scoreMedian human score
WriteHuman100%49 of 49100.0%100%
StealthGPT Super98%49 of 5099.0%100%
Undetectable.ai96%48 of 5094.7%100%
Grubby94%47 of 5093.6%100%
Rephrasy88%44 of 5087.3%100%
RewriteAI86%43 of 5083.3%100%
HIX Bypass68%34 of 5063.6%94.97%
Humbot62%31 of 5060.8%83.18%
BypassGPT56%28 of 5057.4%67.06%
Ryne8%4 of 508.3%0%

Originality.ai turbo

Originality.ai turbo results, September 2026. Same 50 texts for every tool.
HumanizerStrict bypassTexts passedMean human scoreMedian human score
Grubby98%49 of 5098.2%100%
StealthGPT Super98%49 of 5095.8%99.98%
WriteHuman98%48 of 4996.1%99.98%
Undetectable.ai94%47 of 5093.1%99.99%
RewriteAI88%44 of 5091.3%99.99%
Rephrasy86%43 of 5085.1%99.93%
Humbot70%35 of 5069.1%72.15%
BypassGPT66%33 of 5067.9%69.48%
HIX Bypass64%32 of 5065.7%67.85%
Ryne0%0 of 502.1%0.13%

ZeroGPT default

ZeroGPT default results, September 2026. Same 50 texts for every tool.
HumanizerStrict bypassTexts passedMean human scoreMedian human score
BypassGPT100%50 of 5097.2%100%
Humbot100%50 of 5096.7%100%
HIX Bypass100%50 of 5096.5%100%
Grubby100%50 of 5096.0%100%
Undetectable.ai100%50 of 5095.0%100%
WriteHuman100%49 of 4994.8%98.2%
Rephrasy100%50 of 5092.7%100%
StealthGPT Super98%49 of 5091.1%97.2%
RewriteAI88%44 of 5077.3%86.95%
Ryne62%31 of 5056.6%59.65%

Winston AI 5.0

Winston AI 5.0 results, September 2026. Same 50 texts for every tool.
HumanizerStrict bypassTexts passedMean human scoreMedian human score
WriteHuman100%49 of 4999.8%99.83%
Grubby100%50 of 5099.3%99.85%
Rephrasy100%50 of 5098.8%99.78%
BypassGPT100%50 of 5098.0%99.63%
Humbot100%50 of 5097.4%99.71%
StealthGPT Super98%49 of 5097.7%99.81%
Undetectable.ai98%49 of 5097.5%99.84%
HIX Bypass98%49 of 5096.4%99.79%
RewriteAI96%48 of 5095.4%99.69%
Ryne26%13 of 5026.3%0.39%

Quality

Quality pass rates, September 2026. A pass means no issue was found in that dimension on the delivered output. Mean is the average of the 4 pass rates. Reported separately from bypass, and never blended into the ranking.
Humanizer
StealthGPT Super83.5%68%72%98%96%
WriteHuman58.7%22%49%98%65%
Grubby77.5%72%46%98%94%
Rephrasy54.5%36%30%92%60%
Undetectable.ai56.5%26%28%94%78%
RewriteAI72.0%54%40%100%94%
HIX Bypass46.5%18%6%96%66%
Humbot47.5%22%0%98%70%
BypassGPT49.0%22%2%94%78%
Ryne79.0%44%80%98%94%

Downloads

Data licensed CC BY 4.0; scoring code licensed MIT. Source and output text, internal IDs and raw API responses are withheld to limit adversarial reuse. That is a known gap, not a feature.

Verify

git clone https://github.com/StealthGPT-Labs/humanizer-benchmark
cd humanizer-benchmark
python3 scripts/verify_report.py reports/2026-09-30-humanizer-comparison

How to cite

HumanizerEval, “September 2026 review”, published September 30, 2026, https://humanizereval.com/cycles/2026-09/.