Kimi K2 Chat vs o3 Vision: which model should you choose?
We compared Kimi K2 Chat and o3 Vision on price, context window and 12 benchmarks. Kimi K2 Chat has the stronger average benchmark score; Kimi K2 Chat is cheaper on a blended 3:1 basis.
Kimi K2 Chat
Kimi K2 Chat is a multimodal model from Moonshot AI. It offers a 400,000-token context window, costs $5.74 per million input tokens and $22.24 per million output tokens, and averages 82.1 across the index's benchmark suite.
- Input
- $5.74 / 1M
- Output
- $22.24 / 1M
- Context
- 400,000
- Avg score
- 82.1
- Open weights
- Yes
o3 Vision
o3 Vision is a multimodal model from OpenAI. It offers a 1,000,000-token context window, costs $15.24 per million input tokens and $65.25 per million output tokens, and averages 81.8 across the index's benchmark suite.
- Input
- $15.24 / 1M
- Output
- $65.25 / 1M
- Context
- 1,000,000
- Avg score
- 81.8
- Open weights
- No
Specification comparison
| Spec | Kimi K2 Chat | o3 Vision | Edge |
|---|---|---|---|
| Input price / 1M | $5.74 | $15.24 | A |
| Output price / 1M | $22.24 | $65.25 | A |
| Context window | 400,000 | 1,000,000 | B |
| Max output | 4,096 | 8,192 | B |
| Average score | 82.1 | 81.8 | A |
| Arena Elo | 1445.6 | 1436.5 | A |
| Open weights | Yes | No | A |
Benchmark comparison
Kimi K2 Chat wins 7, o3 Vision wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Kimi K2 Chat | o3 Vision | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 82.7 | 83.6 | 0.9 | o3 Vision |
| GPQA Diamond | 77.4 | 77.8 | 0.4 | o3 Vision |
| SWE-bench Verified | 70.0 | 71.8 | 1.8 | o3 Vision |
| HumanEval | 88.1 | 85.6 | 2.5 | Kimi K2 Chat |
| MATH-500 | 84.8 | 84.4 | 0.4 | Kimi K2 Chat |
| AIME 2025 | 84.1 | 82.4 | 1.7 | Kimi K2 Chat |
| LiveCodeBench | 74.5 | 73.7 | 0.8 | Kimi K2 Chat |
| IFEval | 88.0 | 89.3 | 1.3 | o3 Vision |
| TruthfulQA | 82.8 | 85.8 | 3.0 | o3 Vision |
| HellaSwag | 91.6 | 89.7 | 1.9 | Kimi K2 Chat |
| MMMU | 79.6 | 75.7 | 3.9 | Kimi K2 Chat |
| Arena Elo | 1445.6 | 1436.5 | 9.1 | Kimi K2 Chat |
Price analysis
On a blended 3:1 input-to-output basis, Kimi K2 Chat costs about $9.86 per million tokens and o3 Vision costs about $27.74. Kimi K2 Chat is roughly 64% cheaper than o3 Vision. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
o3 Vision has the larger context window at 1,000,000 tokens, compared with 400,000 for Kimi K2 Chat. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Kimi K2 Chat wins 7, o3 Vision wins 5, and 0 are tied. On the index average, Kimi K2 Chat leads o3 Vision by 0.3 points (82.1 versus 81.8).
The price picture favours Kimi K2 Chat. The context picture favours o3 Vision. Those two dimensions often matter more than a few benchmark points once a model is good enough for the task.
If you need a single default, start with Kimi K2 Chat for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Kimi K2 Chat if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
- You need open weights for self-hosting or fine-tuning.
Choose o3 Vision if
- You need the larger 1,000,000-token context window.
- You need the larger 8,192-token output limit.
FAQ
Is Kimi K2 Chat better than o3 Vision?
On the index average, Kimi K2 Chat leads o3 Vision by 0.3 points (82.1 versus 81.8). The better choice depends on price, context and your task. Kimi K2 Chat wins 7 benchmarks, o3 Vision wins 5.
Which is cheaper, Kimi K2 Chat or o3 Vision?
Kimi K2 Chat is cheaper on a blended 3:1 basis at about $9.86 per million tokens, versus $27.74 for o3 Vision.
Which has the larger context window?
o3 Vision has the larger context window at 1,000,000 tokens. Kimi K2 Chat has 400,000 tokens.
Are these models open weights?
Kimi K2 Chat is open weights; o3 Vision is proprietary.
Which should I choose for production?
If you need a single default, start with Kimi K2 Chat for quality-sensitive work, and check whether its price holds at your expected volume before committing.