Claude Fable 5.1 vs Kimi K2.7 Code
Pricing, context window and real answers (September 2026)
Claude Fable 5.1 (Anthropic) 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
 Claude Fable 5.1 |  Kimi K2.7 Code | |
|---|---|---|
| Provider | Anthropic | Moonshot |
| Input (per 1M tokens) | ¥1,787 | ¥55 |
| Output (per 1M tokens) | ¥8,935 | ¥530 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥6,255 | ¥320 |
| Context window | 1,000,000 tokens | 262,144 tokens |
| Release date | 9/1/2026 | 6/12/2026 |
| Input modalities | text, image, file | text, image |
| Arena · overall | #3 · ELO 1,504 | Unranked |
| Arena · Japanese | Unranked | Unranked |
| Arena · coding | #34 · ELO 1,517 | 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, 94% less than Claude Fable 5.1.
- For long documents, Claude Fable 5.1: a 1,000,000-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, Claude Fable 5.1 or Kimi K2.7 Code?
- Per 1M output tokens, Claude Fable 5.1 is ¥8,935 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 Claude Fable 5.1 and Kimi K2.7 Code compare?
- Claude Fable 5.1 takes 1,000,000 tokens; Kimi K2.7 Code takes 262,144.
- Can I use Claude Fable 5.1 and Kimi K2.7 Code with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-fable-5-1" 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 Claude Fable 5.1 and Kimi K2.7 Code from the browser chat and the API. No monthly fee.