Gemini 2.5 Pro vs Kimi K2 Chat: which model should you choose?
We compared Gemini 2.5 Pro and Kimi K2 Chat 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.
Gemini 2.5 Pro
Gemini 2.5 Pro is a multimodal model from Google DeepMind. It offers a 200,000-token context window, costs $15.20 per million input tokens and $57.83 per million output tokens, and averages 81.6 across the index's benchmark suite.
- Input
- $15.20 / 1M
- Output
- $57.83 / 1M
- Context
- 200,000
- Avg score
- 81.6
- Open weights
- No
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
Specification comparison
| Spec | Gemini 2.5 Pro | Kimi K2 Chat | Edge |
|---|---|---|---|
| Input price / 1M | $15.20 | $5.74 | B |
| Output price / 1M | $57.83 | $22.24 | B |
| Context window | 200,000 | 400,000 | B |
| Max output | 16,384 | 4,096 | A |
| Average score | 81.6 | 82.1 | B |
| Arena Elo | 1455.0 | 1445.6 | A |
| Open weights | No | Yes | B |
Benchmark comparison
Gemini 2.5 Pro wins 6, Kimi K2 Chat wins 5, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Gemini 2.5 Pro | Kimi K2 Chat | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 83.6 | 82.7 | 0.9 | Gemini 2.5 Pro |
| GPQA Diamond | 76.5 | 77.4 | 0.9 | Kimi K2 Chat |
| SWE-bench Verified | 70.2 | 70.0 | 0.2 | Gemini 2.5 Pro |
| HumanEval | 87.7 | 88.1 | 0.4 | Kimi K2 Chat |
| MATH-500 | 86.8 | 84.8 | 2.0 | Gemini 2.5 Pro |
| AIME 2025 | 76.1 | 84.1 | 8.0 | Kimi K2 Chat |
| LiveCodeBench | 76.2 | 74.5 | 1.7 | Gemini 2.5 Pro |
| IFEval | 87.6 | 88.0 | 0.4 | Kimi K2 Chat |
| TruthfulQA | 82.8 | 82.8 | 0.0 | Tie |
| HellaSwag | 89.7 | 91.6 | 1.9 | Kimi K2 Chat |
| MMMU | 80.5 | 79.6 | 0.9 | Gemini 2.5 Pro |
| Arena Elo | 1455.0 | 1445.6 | 9.4 | Gemini 2.5 Pro |
Price analysis
On a blended 3:1 input-to-output basis, Gemini 2.5 Pro costs about $25.86 per million tokens and Kimi K2 Chat costs about $9.86. Kimi K2 Chat is roughly 62% cheaper than Gemini 2.5 Pro. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Kimi K2 Chat has the larger context window at 400,000 tokens, compared with 200,000 for Gemini 2.5 Pro. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Gemini 2.5 Pro wins 6, Kimi K2 Chat wins 5, and 1 are tied. On the index average, Kimi K2 Chat leads Gemini 2.5 Pro by 0.5 points (82.1 versus 81.6).
The price picture favours Kimi K2 Chat. The context picture favours Kimi K2 Chat. 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 Gemini 2.5 Pro if
- You need the larger 16,384-token output limit.
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 the larger 400,000-token context window.
- You need open weights for self-hosting or fine-tuning.
FAQ
Is Gemini 2.5 Pro better than Kimi K2 Chat?
On the index average, Kimi K2 Chat leads Gemini 2.5 Pro by 0.5 points (82.1 versus 81.6). The better choice depends on price, context and your task. Gemini 2.5 Pro wins 6 benchmarks, Kimi K2 Chat wins 5.
Which is cheaper, Gemini 2.5 Pro or Kimi K2 Chat?
Kimi K2 Chat is cheaper on a blended 3:1 basis at about $9.86 per million tokens, versus $25.86 for Gemini 2.5 Pro.
Which has the larger context window?
Kimi K2 Chat has the larger context window at 400,000 tokens. Gemini 2.5 Pro has 200,000 tokens.
Are these models open weights?
Gemini 2.5 Pro is proprietary; Kimi K2 Chat is open weights.
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.