Muse Spark Open
Meta's open-weight release of Muse Spark: an 816B multimodal MoE
Context window
1M
Input / 1M tokens
$1.25
Output / 1M tokens
$4.25
Provider
Meta
Open weights on Hugging Face (meta-models/Muse-Spark-open-816B-A42B) under the Muse Model License, which has limited commercial terms. Hosted price shown is OpenRouter. · Data verified 2026-10-17
Muse Spark Open (October 15, 2026) is Meta's open-weight release of its Muse Spark model: an 816B-parameter Mixture-of-Experts with 42B active per token, a 1M-token context, and native text, image, audio and video input. It shares its base with Muse Spark 1.3 plus extra safety post-training, and Artificial Analysis rates it the strongest US open-weight model at release.
Capability index
Relative estimates (0-100) to place this model against its peers, grounded in published benchmarks.
How to access it
Weights on Hugging Face; hosted on OpenRouter as meta/muse-spark-open.
Strengths
- ✓Strongest US open-weight model at release (Artificial Analysis index 39)
- ✓Natively multimodal: text, image, audio, video
- ✓1M-token context
Best for developers who...
Benchmarks
| Benchmark | Score | Notes |
|---|---|---|
| Artificial Analysis Intelligence Index | 39 | Third-party |
Source: PyTorch blog
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