Claude Opus 4.7 vs Kimi K2.6
Pricing, context window and real answers (August 2026)
Claude Opus 4.7 (Anthropic) and Kimi K2.6 (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
 Claude Opus 4.7 |  Kimi K2.6 | |
|---|---|---|
| Provider | Anthropic | Moonshot |
| Input (per 1M tokens) | ¥840 | ¥169.77 |
| Output (per 1M tokens) | ¥4,200 | ¥714.8 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥2,940 | ¥527 |
| Context window | 1,000,000 tokens | 262,144 tokens |
| Release date | 4/16/2026 | 4/20/2026 |
| Input modalities | text, image, file | text, image |
| Arena · overall | #6 · ELO 1,494 | #49 · ELO 1,461 |
| Arena · Japanese | #18 · ELO 1,478 | #35 · ELO 1,445 |
| Arena · coding | #4 · ELO 1,547 | #34 · ELO 1,514 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Kimi K2.6: ¥714.8 per 1M output tokens, 83% less than Claude Opus 4.7.
- On the Overall arena board, Claude Opus 4.7 ranks higher (#6; Kimi K2.6 is #49).
- On the Japanese arena board, Claude Opus 4.7 ranks higher (#18; Kimi K2.6 is #35).
- On the Coding arena board, Claude Opus 4.7 ranks higher (#4; Kimi K2.6 is #34).
- For long documents, Claude Opus 4.7: a 1,000,000-token context window against 262,144 for Kimi K2.6.
- 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, Claude Opus 4.7 or Kimi K2.6?
- Per 1M output tokens, Claude Opus 4.7 is ¥4,200 and Kimi K2.6 is ¥714.8 on FastMetal (yen, before tax), so Kimi K2.6 is cheaper.
- How do the context windows of Claude Opus 4.7 and Kimi K2.6 compare?
- Claude Opus 4.7 takes 1,000,000 tokens; Kimi K2.6 takes 262,144.
- Which ranks higher, Claude Opus 4.7 or Kimi K2.6?
- Claude Opus 4.7 ranks higher on the public arena (Claude Opus 4.7 #18, Kimi K2.6 #35). Ranks move as the leaderboard updates.
- Can I use Claude Opus 4.7 and Kimi K2.6 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-opus-4-7" or "kimi-k2.6" 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 Claude Opus 4.7 and Kimi K2.6 from the browser chat and the API. No monthly fee.