Kimi K2 Thinking vs OpenAI o4-mini
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Moonshot AI · Nov 2025
A trillion-parameter open reasoning agent that can chain 200–300 tool calls — the open-weights agentic standout of late 2025.
OpenAI · Apr 2025
A compact reasoning model that punched far above its price on math — 92.7% on AIME 2025 at $1.10 per million input tokens.
The verdict
Kimi K2 Thinking wins 3 of the 3 benchmarks these models share, against 0 for OpenAI o4-mini. Kimi K2 Thinking is about 1.8x cheaper per blended million tokens (3:1 input:output mix). Kimi K2 Thinking also takes 262K of context versus 200K for OpenAI o4-mini. And Kimi K2 Thinking is open-weights (Modified MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Benchmark head-to-head 3–0
Specs & pricing
| Kimi K2 Thinking | OpenAI o4-mini | |
|---|---|---|
| modhub Index | 67.6 | 80.9 |
| Input price / 1M | $0.6 | $1.1 |
| Output price / 1M | $2.5 | $4.4 |
| Context window | 262K | 200K |
| Max output | — | 100K |
| Open weights | yes (Modified MIT) | no |
| Reasoning model | yes | yes |
| Multimodal input | text | text, image |
| Knowledge cutoff | Apr 2025 | May 2024 |
| Released | Nov 2025 | Apr 2025 |
| Example monthly cost* | $9.75 | $17.60 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Kimi K2 Thinking or OpenAI o4-mini?
- Kimi K2 Thinking wins 3 of the 3 benchmarks these models share, against 0 for OpenAI o4-mini. Kimi K2 Thinking is about 1.8x cheaper per blended million tokens (3:1 input:output mix). Kimi K2 Thinking also takes 262K of context versus 200K for OpenAI o4-mini. And Kimi K2 Thinking is open-weights (Modified MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
- Which is cheaper, Kimi K2 Thinking or OpenAI o4-mini?
- Kimi K2 Thinking costs $0.6/$2.5 per million input/output tokens, while OpenAI o4-mini costs $1.1/$4.4. For a typical workload of 10M input and 1.5M output tokens per month, that's $9.75 versus $17.60.
- Which model is better for coding, Kimi K2 Thinking or OpenAI o4-mini?
- On SWE-bench Verified — the standard agentic-coding benchmark — Kimi K2 Thinking scores 71.3% versus 68.1% for OpenAI o4-mini, making Kimi K2 Thinking the stronger pick for coding agents.