Z.ai: GLM 5 vs GPT-5.1
Compare Z.ai: GLM 5 by Zhipu AI against GPT-5.1 by OpenAI, context windows of 203K vs 400K, tested across 51 shared challenges.
Our Verdict
Z.ai: GLM 5
GPT-5.1
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Z.ai: GLM 5 is 3.9x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Z.ai: GLM 5
Input
$0.80
1.6× cheaper
Output
$2.56
3.9× cheaper
GPT-5.1
Input
$1.25
Output
$10.00
Z.ai: GLM 5 is cheaper on both — 1.6× input, 3.9× output
Writing DNA
Style Comparison
Similarity
41%
Z.ai: GLM 5 uses 6.5x more transitions
Z.ai: GLM 5
GPT-5.1
54%Vocabulary62%
17wSentence Length19w
0.37Hedging0.29
6.3Bold3.5
4.7Lists7.2
0.00Emoji0.00
0.60Headings0.61
0.18Transitions0.03
Based on 22 + 14 text responses
Research
What we learned reading every model
FAQ
