Gemini 3.1 Pro Preview vs Kimi K2.7 Code
Pricing, context window and real answers (September 2026)
Gemini 3.1 Pro Preview (Google) and Kimi K2.7 Code (Moonshot), compared as you can actually call them on FastMetal. Both are served from the same OpenAI-compatible endpoint and API key; switching is a change to the model string.
Specs and pricing
 Gemini 3.1 Pro Preview |  Kimi K2.7 Code | |
|---|---|---|
| Provider | Moonshot | |
| Input (per 1M tokens) | ¥357.4 | ¥55 |
| Output (per 1M tokens) | ¥2,144.4 | ¥530 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥1,430 | ¥320 |
| Context window | 1,048,576 tokens | 262,144 tokens |
| Release date | 2/19/2026 | 6/12/2026 |
| Input modalities | audio, file, image, text, video | text, image |
| Throughput (p50) | — | — |
| Arena · overall | #15 · ELO 1,487 | Unranked |
| Arena · Japanese | #9 · ELO 1,494 | Unranked |
| Arena · coding | #28 · ELO 1,520 | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Kimi K2.7 Code: ¥530 per 1M output tokens, 75% less than Gemini 3.1 Pro Preview.
- For long documents, Gemini 3.1 Pro Preview: a 1,048,576-token context window against 262,144 for Kimi K2.7 Code.
- If in doubt, try both on the same key. Switching is a change to the model string, and each is billed at its own rate.
Frequently asked questions
- Which is cheaper, Gemini 3.1 Pro Preview or Kimi K2.7 Code?
- Per 1M output tokens, Gemini 3.1 Pro Preview is ¥2,144.4 and Kimi K2.7 Code is ¥530 on FastMetal (yen, before tax), so Kimi K2.7 Code is cheaper.
- How do the context windows of Gemini 3.1 Pro Preview and Kimi K2.7 Code compare?
- Gemini 3.1 Pro Preview takes 1,048,576 tokens; Kimi K2.7 Code takes 262,144.
- Can I use Gemini 3.1 Pro Preview and Kimi K2.7 Code with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gemini-3.1-pro-preview" or "japan-kimi-k2.7-code" as the model. Each is billed at its own rate from the same prepaid balance.
Try both on one API key
Create an account and add credit to call Gemini 3.1 Pro Preview and Kimi K2.7 Code from the browser chat and the API. No monthly fee.