Z.AI: GLM 4.5 Air vs GPT-5.1 Chat
Compare Z.AI: GLM 4.5 Air by Zhipu AI against GPT-5.1 Chat by OpenAI, context windows of 128K vs 128K, tested across 52 shared challenges.
Our Verdict
Z.AI: GLM 4.5 Air
GPT-5.1 Chat
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 4.5 Air is 9.1x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Z.AI: GLM 4.5 Air
Input
$0.20
6.3× cheaper
Output
$1.10
9.1× cheaper
GPT-5.1 Chat
Input
$1.25
Output
$10.00
Z.AI: GLM 4.5 Air is cheaper on both — 6.3× input, 9.1× output
Writing DNA
Style Comparison
Similarity
15%
Z.AI: GLM 4.5 Air uses 9.9x more emoji
Z.AI: GLM 4.5 Air
GPT-5.1 Chat
48%Vocabulary73%
16wSentence Length18w
0.40Hedging0.45
5.4Bold1.1
4.8Lists2.4
0.10Emoji0.00
0.75Headings0.00
0.12Transitions0.06
Based on 15 + 15 text responses
Research
What we learned reading every model
FAQ
