Z.ai: GLM 5.1 vs xAI: Grok 4
Compare Z.ai: GLM 5.1 by Z-ai against xAI: Grok 4 by xAI, context windows of 203K vs 256K, tested across 52 shared challenges.
Our Verdict
Z.ai: GLM 5.1
xAI: Grok 4
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 5.1 is 3.4x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Z.ai: GLM 5.1
Input
$1.40
2.1× cheaper
Output
$4.40
3.4× cheaper
xAI: Grok 4
Input
$3.00
Output
$15.00
Z.ai: GLM 5.1 is cheaper on both — 2.1× input, 3.4× output
Writing DNA
Style Comparison
Similarity
54%
xAI: Grok 4 uses 7.0x more emoji
Z.ai: GLM 5.1
xAI: Grok 4
54%Vocabulary53%
18wSentence Length18w
0.31Hedging0.67
3.6Bold2.7
2.6Lists2.7
0.00Emoji0.07
0.43Headings0.86
0.11Transitions0.04
Based on 27 + 21 text responses
Research
What we learned reading every model
FAQ
Common questions
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