Claude Opus 4.7 vs Muse Spark 1.2
Pricing, context window and real answers (August 2026)
Claude Opus 4.7 (Anthropic) and Muse Spark 1.2 (Meta), 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 |  Muse Spark 1.2 | |
|---|---|---|
| Provider | Anthropic | Meta |
| Input (per 1M tokens) | ¥840 | ¥219.9 |
| Output (per 1M tokens) | ¥4,200 | ¥747.65 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥2,940 | ¥594 |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Release date | 4/16/2026 | 8/5/2026 |
| Input modalities | text, image, file | text, image, video, file, audio |
| Arena · overall | #6 · ELO 1,494 | #4 · ELO 1,498 |
| Arena · Japanese | #18 · ELO 1,478 | Unranked |
| Arena · coding | #4 · ELO 1,547 | #7 · ELO 1,533 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Muse Spark 1.2: ¥747.65 per 1M output tokens, 82% less than Claude Opus 4.7.
- On the Overall arena board, Muse Spark 1.2 ranks higher (#4; Claude Opus 4.7 is #6).
- On the Coding arena board, Claude Opus 4.7 ranks higher (#4; Muse Spark 1.2 is #7).
- For long documents, Muse Spark 1.2: a 1,048,576-token context window against 1,000,000 for Claude Opus 4.7.
- 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 Muse Spark 1.2?
- Per 1M output tokens, Claude Opus 4.7 is ¥4,200 and Muse Spark 1.2 is ¥747.65 on FastMetal (yen, before tax), so Muse Spark 1.2 is cheaper.
- How do the context windows of Claude Opus 4.7 and Muse Spark 1.2 compare?
- Claude Opus 4.7 takes 1,000,000 tokens; Muse Spark 1.2 takes 1,048,576.
- Which ranks higher, Claude Opus 4.7 or Muse Spark 1.2?
- Muse Spark 1.2 ranks higher on the public arena (Claude Opus 4.7 #18, Muse Spark 1.2 #4). Ranks move as the leaderboard updates.
- Can I use Claude Opus 4.7 and Muse Spark 1.2 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-opus-4-7" or "muse-spark-1.2" 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 Muse Spark 1.2 from the browser chat and the API. No monthly fee.