Kimi K2.7 Code vs Mercury 2.5
Pricing, context window and real answers (September 2026)
Kimi K2.7 Code (Moonshot) and Mercury 2.5 (Inception), 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
 Kimi K2.7 Code | Mercury 2.5 | |
|---|---|---|
| Provider | Moonshot | Inception |
| Input (per 1M tokens) | ¥55 | ¥6.77 |
| Output (per 1M tokens) | ¥530 | ¥25.38 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥320 | ¥19 |
| Context window | 262,144 tokens | 260,000 tokens |
| Release date | 6/12/2026 | 9/8/2026 |
| Input modalities | text, image | text |
| Arena · overall | Unranked | Unranked |
| Arena · Japanese | Unranked | Unranked |
| Arena · coding | Unranked | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Mercury 2.5: ¥25.38 per 1M output tokens, 95% less than Kimi K2.7 Code.
- For long documents, Kimi K2.7 Code: a 262,144-token context window against 260,000 for Mercury 2.5.
- 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, Kimi K2.7 Code or Mercury 2.5?
- Per 1M output tokens, Kimi K2.7 Code is ¥530 and Mercury 2.5 is ¥25.38 on FastMetal (yen, before tax), so Mercury 2.5 is cheaper.
- How do the context windows of Kimi K2.7 Code and Mercury 2.5 compare?
- Kimi K2.7 Code takes 262,144 tokens; Mercury 2.5 takes 260,000.
- Can I use Kimi K2.7 Code and Mercury 2.5 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "japan-kimi-k2.7-code" or "mercury-2.5" 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 Kimi K2.7 Code and Mercury 2.5 from the browser chat and the API. No monthly fee.