AI Humanizer Benchmark

Leaderboard / Compare / GPTinf vs UndetectedGPT

Head to head · September 2026 cycle

GPTinf vs UndetectedGPT

UndetectedGPT finished 6.6 points ahead of GPTinf in the September 2026 cycle, 84.90 to 78.30, ranking #1 against #4 in a field of 11. UndetectedGPT scored higher on 4 of 7 detectors and 7 of 7 writing categories. GPTinf came out ahead on Copyleaks (57.6 vs 21.2), Winston AI (63.0 vs 54.4), ZeroGPT (85.2 vs 85.1). The bypass-rate gap, 79.9 to 86.3, sits inside both tools' 95% confidence intervals, so treat bypass as a draw.

78.30/100
Overall score
#4/11
Rank
+6.6
UndetectedGPT leads
Detectors
34
Categories
07
Components
04
UndetectedGPTLeads
undetectedgpt.ai
84.90/100
Overall score
#1/11
Rank
Last tested
2026-09-03
Prompts
33
Methodology
v1.0.0

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

GPTinfUndetectedGPT
Bypass rateCIs overlapUndetectedGPT by 6.4
79.9
86.3
Meaning preservationUndetectedGPT by 9.1
75.7
84.8
ReadabilityUndetectedGPT by 0.6
76.7
77.3
ConsistencyUndetectedGPT by 9.2
82.2
91.5
Penaltiesfewer is bettertied
None
None

CIs overlap marks a gap that sits inside both tools' 95% confidence intervals for bypass rate; it may not survive another cycle.

Detector by detector

Share of each tool's outputs that a detector classified as human-written. UndetectedGPT took 4 of 7.

GPTinfUndetectedGPT
GPTZeroUndetectedGPT by 10.2
69.8
80.0
Winston AIGPTinf by 8.5
63.0
54.4
Originality.aiUndetectedGPT by 45.4
33.8
79.2
ZeroGPTGPTinf by 0.1
85.2
85.1
GrammarlyUndetectedGPT by 1.7
87.6
89.3
QuillBotUndetectedGPT by 7.8
84.9
92.7
CopyleaksGPTinf by 36.4
57.6
21.2

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.

Academic essayApplication essayBlog postBusiness emailMarketing copyDiscussion boardNews article
GPTinfUndetectedGPTOuter ring = 100
GPTinfUndetectedGPT
Academic essay6 promptsUndetectedGPT by 3.9
85.3
89.2
Application essay6 promptsUndetectedGPT by 6.7
79.5
86.2
Blog post6 promptsUndetectedGPT by 2.6
75.0
77.6
Business email3 promptsUndetectedGPT by 17.9
61.8
79.7
Marketing copy6 promptsUndetectedGPT by 4.1
81.7
85.8
Discussion board3 promptsUndetectedGPT by 7.4
82.9
90.3
News article3 promptsUndetectedGPT by 12.7
73.2
85.9

Where each one wins

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

GPTinf

3 wins
  • Copyleaks Detector57.6 vs 21.2
  • Winston AI Detector63.0 vs 54.4
  • ZeroGPT Detector85.2 vs 85.1

UndetectedGPT

15 wins
  • Consistency Score91.5 vs 82.2
  • Meaning preservation Score84.8 vs 75.7
  • Bypass rate Score86.3 vs 79.9
  • Readability Score77.3 vs 76.7
  • Originality.ai Detector79.2 vs 33.8
  • GPTZero Detector80.0 vs 69.8
  • QuillBot Detector92.7 vs 84.9
  • Grammarly Detector89.3 vs 87.6
  • Business email Category79.7 vs 61.8
  • News article Category85.9 vs 73.2
  • Discussion board Category90.3 vs 82.9
  • Application essay Category86.2 vs 79.5
  • Marketing copy Category85.8 vs 81.7
  • Academic essay Category89.2 vs 85.3
  • Blog post Category77.6 vs 75.0

Questions people ask

Is GPTinf better than UndetectedGPT?

UndetectedGPT finished 6.6 points ahead of GPTinf in the September 2026 cycle, 84.90 to 78.30, ranking #1 against #4 in a field of 11. UndetectedGPT scored higher on 4 of 7 detectors and 7 of 7 writing categories. Both tools ran the same 33 prompts, scored by the same 7 detectors, under methodology v1.0.0; every input, output, and verdict is published.

Which bypasses AI detectors better, GPTinf or UndetectedGPT?

UndetectedGPT posted the higher bypass rate, 86.3 vs 79.9, and scored higher on 4 of 7 detectors. GPTinf led on Winston AI, ZeroGPT and Copyleaks; UndetectedGPT led on GPTZero, Originality.ai, Grammarly and QuillBot. The overall bypass gap is inside both 95% confidence intervals, so it is not a reliable difference.

Do GPTinf and UndetectedGPT keep the original meaning?

UndetectedGPT preserved meaning better, 84.8 vs 75.7 on our 0–100 similarity scale. On readability, UndetectedGPT rated higher, 77.3 vs 76.7. Penalties this cycle: GPTinf None, UndetectedGPT None.

More matchups

Add a third tool to this comparison·Every matchup

Go deeper