Claude Opus 5 vs Muse Spark 1.1
Head-to-head technical comparison of intelligence, capabilities, and API pricing.
Which should you use?
Claude Opus 5 leads on the composite index by 4.3 points (96.6 vs 92.3).
Their Arena Elo differs by only 1 points, inside the confidence intervals the public board reports, so human preference does not separate them.
Cost is the sharper difference: Claude Opus 5 is 4x the input price of Muse Spark 1.1 ($5 against $1.25 per 1M), so at volume the choice is usually decided by budget rather than benchmarks.
Pick Claude Opus 5 when
- Higher composite index — 96.6 against 92.3, a gap of 4.3 points.
- Stronger on MMLU-Pro: 95.7% against 91.9%.
Pick Muse Spark 1.1 when
- Cheaper input tokens — $1.25 against $5 per 1M, so Claude Opus 5 costs 4x as much to feed.
- Better value per point of measured capability: $0.014 per index point against $0.052.
Value per point of measured capability, at list input pricing: Muse Spark 1.1 $0.014 · Claude Opus 5 $0.052 per index point. Run your own token mix through the token cost calculator — a comparison at list price ignores caching and batch discounts, which move real bills more than this gap does.
Where these numbers come from
Figures as of 2026-09-07. Arena Elo and pricing are read from the public board and each vendor's own pricing page; see the full leaderboard for all 34 models and which columns are measured rather than estimated, or the benchmark matrix for scores benchmark by benchmark.
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