Gemini 3.1 Pro vs Kimi K3
Both are Flagship-tier models, from Google and Moonshot AI respectively. Gemini 3.1 Pro is the cheaper choice overall at a 4:1 input:output ratio.
Which is cheaper
- Input price: Gemini 3.1 Pro is cheaper ($2.00 vs $3.00).
- Output price: Gemini 3.1 Pro is cheaper ($12.00 vs $15.00).
- Blended, 4:1 input:output ratio: Gemini 3.1 Pro is 25.9% cheaper ($4.00 vs $5.40 per weighted 1M tokens).
Side by side
| Spec | Gemini 3.1 Pro | Kimi K3 |
|---|---|---|
| Provider | Moonshot AI | |
| Tier | Flagship | Flagship |
| Context window | 1M | 1.05M |
| Max output | 66K | — |
| Input $/1M | $2.00 | $3.00 |
| Output $/1M | $12.00 | $15.00 |
| Cache read $/1M | $0.20 | $0.30 |
| Modalities | text, image | text |
Gemini 3.1 Pro. Listed as gemini-3.1-pro-preview. Standard tier for prompts up to 200K tokens; above that, $4 input / $18 output and $0.40 cache read per 1M. Cached context is also billed for storage at $4.50 per 1M tokens per hour.
Kimi K3. input is cache-miss (standard) price per 1M tokens; cache_read is cache-hit price ($0.30).
Sources
Gemini 3.1 Pro — verified August 29, 2026
Kimi K3 — verified August 29, 2026
Full Gemini 3.1 Pro pricing page → · Full Kimi K3 pricing page →