Z.ai: GLM 5.2 vs GPT-5.1-Codex
Compare Z.ai: GLM 5.2 by Zhipu AI against GPT-5.1-Codex by OpenAI, context windows of 1.0M vs 400K, tested across 52 shared challenges.
Our Verdict
Z.ai: GLM 5.2
GPT-5.1-CodexRunner-up
No community votes yet. On paper, Z.ai: GLM 5.2 has the edge — newer, bigger context window.
Too close to call
API pricing
Cost per 1M tokens
Z.ai: GLM 5.2
Input
$1.40
Output
$4.40
2.3× cheaper
GPT-5.1-Codex
Input
$1.25
1.1× cheaper
Output
$10.00
GPT-5.1-Codex wins input (1.1× cheaper)·Z.ai: GLM 5.2 wins output (2.3× cheaper)
Writing DNA
Style Comparison
Similarity
56%
GPT-5.1-Codex uses 1.6x more transitions
Z.ai: GLM 5.2
GPT-5.1-Codex
56%Vocabulary70%
18wSentence Length17w
0.27Hedging0.39
3.7Bold3.4
2.8Lists3.5
0.00Emoji0.00
0.56Headings0.50
0.24Transitions0.38
Based on 27 + 14 text responses
Research
What we learned reading every model
FAQ
