Meta releases Muse Spark Open: 816B-parameter open model tops US open-weight rankings
arena · x · 2026-10-18
Meta has released Muse Spark Open, its most capable US open-weight model to date, built for coding and agentic work with strengths in long-horizon tasks, complex software engineering, and multi-step reasoning.
Key specs
- 816B total / 42B active parameters (MoE)
- 1M token context window
- Natively multimodal across text, image, video, and audio
Benchmarks
On Code Arena: WebDev, it scores 1511 points — #13 among open models overall and the #1 US open model, 156 points above Meta's earlier open model Muse Glimmer (1355). By domain: #13 in Brand & Marketing and Data & Analytics, #14 in Reference-Based Design, #15 in Gaming and Consumer Product, #20 in Simulations.
Pricing
$1.25/$4.25 per 1M input/output tokens — 79% cheaper than Muse Wonder (Max) and on par with Muse Spark 1.3 (Max).
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