GPT-5.1 vs MoonshotAI: Kimi K2 0905
Compare GPT-5.1 by OpenAI against MoonshotAI: Kimi K2 0905 by Moonshot AI, context windows of 400K vs 262K, tested across 52 shared challenges.
Our Verdict
GPT-5.1
MoonshotAI: Kimi K2 0905Runner-up
No community votes yet. On paper, GPT-5.1 has the edge — newer, bigger context window, major provider backing.
MoonshotAI: Kimi K2 0905 is 4.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.1
Input
$1.25
Output
$10.00
MoonshotAI: Kimi K2 0905
Input
$0.60
2.1× cheaper
Output
$2.50
4.0× cheaper
MoonshotAI: Kimi K2 0905 is cheaper on both — 2.1× input, 4.0× output
Writing DNA
Style Comparison
Similarity
47%
MoonshotAI: Kimi K2 0905 uses 14.6x more emoji
GPT-5.1
MoonshotAI: Kimi K2 0905
62%Vocabulary62%
19wSentence Length19w
0.29Hedging0.17
3.5Bold3.3
7.2Lists3.4
0.00Emoji0.15
0.61Headings0.83
0.03Transitions0.06
Based on 14 + 22 text responses
Research
What we learned reading every model
FAQ
