GPT-5.1 vs Kimi K2 Instruct
OpenAI vs Moonshot AI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 66.5)
- •Kimi K2 Instruct is cheaper ($0.57 vs $1.25 per 1M input)
- •GPT-5.1 is faster
- •GPT-5.1 has a larger context window (400K)
| GPT-5.1 | Kimi K2 Instruct | |
|---|---|---|
| Intelligence index | 89 | 66.5 |
| Developer | OpenAI | Moonshot AI |
| Type | LLM | LLM |
| Access | API only | Open weights |
| Context window | 400,000 tokens | 131,072 tokens |
| Input price | $1.25 / 1M | $0.57 / 1M |
| Output price | $10.00 / 1M | $2.30 / 1M |
| Speed | 115 tok/s | 45 tok/s |
| Released | November 12, 2025 | July 11, 2025 |
| Parameters | — | 1000000000000 |
| Input modalities | Text, Image | — |
| Output modalities | Text | — |
Shared benchmarks
GPT-5.1
Kimi K2 Instruct
AIME 2025
94
49.5
GPQA Diamond
88.1
75.1
Humanity’s Last Exam
26.5
4.7
MMLU-Pro
87
81.1