DeepSeek V4 Flash vs Z.ai: GLM 5.1
Compare DeepSeek V4 Flash by DeepSeek against Z.ai: GLM 5.1 by Z-ai, context windows of 1.0M vs 203K, tested across 53 shared challenges.
Our Verdict
DeepSeek V4 Flash
Z.ai: GLM 5.1Runner-up
No community votes yet. On paper, DeepSeek V4 Flash has the edge — bigger context window, major provider backing.
DeepSeek V4 Flash is 16x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
DeepSeek V4 Flash
Input
$0.14
10.0× cheaper
Output
$0.28
16× cheaper
Z.ai: GLM 5.1
Input
$1.40
Output
$4.40
DeepSeek V4 Flash is cheaper on both — 10.0× input, 16× output
Writing DNA
Style Comparison
Similarity
76%
DeepSeek V4 Flash uses 1.8x more transitions
DeepSeek V4 Flash
Z.ai: GLM 5.1
54%Vocabulary54%
17wSentence Length18w
0.52Hedging0.31
3.6Bold3.6
2.6Lists2.6
0.00Emoji0.00
0.41Headings0.43
0.19Transitions0.11
Based on 27 + 27 text responses
Research
What we learned reading every model
FAQ
