Kimi K2 0905 is $1.4 cheaper per 1M input tokens (70% lower; 3.33x difference).
API cost decision in 10 seconds
Gemini 3.1 Pro Preview vs Kimi K2 0905
Pick Kimi K2 0905 for lower cost; pick Gemini 3.1 Pro Preview only if the larger context window matters more.
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Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick Kimi K2 0905 for lower cost; pick Gemini 3.1 Pro Preview only if the larger context window matters more.
On the standard 1M input plus 500K output workload, Kimi K2 0905 is estimated at $1.85 vs $8 for Gemini 3.1 Pro Preview, saving $6.15 (76.9% lower).
Cost-first pickKimi K2 0905
Context-first pickGemini 3.1 Pro Preview
Sample savings$6.1576.9%
10x traffic gap$61.5
Gemini 3.1 Pro Preview has more context, but Kimi K2 0905 saves $6.15 on the standard workload. At 10x that traffic, the same price gap is about $61.5. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Kimi K2 0905 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | Gemini 3.1 Pro Preview | Kimi K2 0905 |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Kimi K2 0905 | $16 | $4.25 |
| Balanced workload | 1M input + 1M output | Kimi K2 0905 | $14 | $3.1 |
| Output-heavy chatbot | 1M input + 5M output | Kimi K2 0905 | $62 | $13.1 |
Kimi K2 0905 is $9.5 cheaper per 1M output tokens (79.2% lower; 4.8x difference).
Gemini 3.1 Pro Preview has 786.43K more context (4x larger).
Kimi K2 0905 is $6.15 cheaper on the standard workload (76.9% lower).
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
Kimi K2 0905 has the lower input price; Kimi K2 0905 has the lower output price; Gemini 3.1 Pro Preview offers the larger context window. For the 1M input plus 500K output sample, Kimi K2 0905 is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $8 for Gemini 3.1 Pro Preview and $1.85 for Kimi K2 0905.
Choose Gemini 3.1 Pro Preview when you care most about larger context window.
Choose Kimi K2 0905 when you care most about lower input-token price, and lower output-token price.
- On the standard 1M input plus 500K output workload, Kimi K2 0905 is estimated at $1.85 vs $8 for Gemini 3.1 Pro Preview, saving $6.15 (76.9% lower).
- Kimi K2 0905 is $6.15 cheaper on the standard workload (76.9% lower).
- Kimi K2 0905 is $1.4 cheaper per 1M input tokens (70% lower; 3.33x difference).
- Kimi K2 0905 is $9.5 cheaper per 1M output tokens (79.2% lower; 4.8x difference).
- Gemini 3.1 Pro Preview has 786.43K more context (4x larger).
| Feature | Gemini 3.1 Pro Preview (Google) | Kimi K2 0905 (MoonshotAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $2 | $0.6 |
| Completion Price per 1M tokens | $12 | $2.5 |
| Sample Workload Cost 1M input + 500K output | $8 | $1.85 |
| Context Window | 1.05M | 262.14K |
| Release Date | ||
| Popularity | #28 | #70 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Kimi K2 0905 | On the standard 1M input plus 500K output workload, Kimi K2 0905 is estimated at $1.85 vs $8 for Gemini 3.1 Pro Preview, saving $6.15 (76.9% lower). |
| High-volume input processing | Kimi K2 0905 | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | Kimi K2 0905 | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Gemini 3.1 Pro Preview | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
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- GPT-5.4 offers 1.05M context with $10 sample workload cost.
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