AI from the other labs · 31 October 2026

Meta releases Muse Spark Open weights, 816B parameters

Meta released Muse Spark Open on 15 October 2026, with weights on Hugging Face. This is a late catch.

Secondary coverage gives 816 billion total parameters, 42 billion active per token and a 1M-token context window. It is also offered on Amazon SageMaker AI, Google Cloud Model Garden and Microsoft Foundry Models. Reports say it is strongest at agentic work with tools and weaker at software engineering. Meta is reported to call it the most capable US open-weight model to date.

Licence

It is not open source. The Muse Model License carries conditions a standard open licence does not, including attribution and a revenue threshold for model-as-a-service providers, per reports. Hugging Face downloads need a login and personal or company details.

Hardware

Sources disagree. One says the compressed version needs at least 700 GB of memory, another more than 256 GB, and a third says Hugging Face ran a 2-bit version on a 512 GB M3 Ultra at 18 tokens a second. For local use, coverage points to Meta's smaller 30B Muse Glimmer.

I could not read Meta's model card, so the figures above are from outlets, not Meta.

Sources

• Itdaily: Meta makes Muse Spark available as open-weight
• Pasquale Pillitteri: Meta releases Muse Spark Open
• i-Scoop: Muse Spark Open