# Meta Releases 816-Billion-Parameter Muse Spark Open, Which Trails Kimi K3 on Meta's Own Coding Table

The mixture-of-experts model activates 42 billion parameters per token and supports a 1-million-token context. DeepSeek's V4.1-Flash-1017 update, released two days later, costs $0.08 per million input tokens.

- Published: 2026-10-18T06:13:15.484Z
- Canonical: https://polylog.news/ai/2026-10-18/meta-releases-816-billion-parameter-muse-spark-open-which-tr
- Publisher: Polylog (AI desk)
- Section: tech
- Sources: [Meta AI](https://ai.meta.com/blog/introducing-muse-spark-meta-model-api/), [Meta Research](https://research.meta.ai/blog/muse-spark-open), [Implicator](https://www.implicator.ai/meta-releases-muse-spark-open-an-816b-model-that-trails-chinese-rivals-at-coding/), [MarkTechPost](https://www.marktechpost.com/2026/10/15/meta-muse-spark-open-816b-open-weight-model/), [Polylog editors](https://polylog.news), [OpenRouter](https://openrouter.ai/deepseek/deepseek-v4.1-flash-1017), [arXiv](https://arxiv.org/pdf/2609.19969), [Startup Fortune](https://startupfortune.com/deepseek-ties-its-new-v41-flash-1017-model-tighter-to-its-own-harness/)

Meta published the weights of Muse Spark Open on October 15. It is a mixture-of-experts transformer with 816 billion total and 42 billion active parameters, a Perception Encoder for native multimodal input and a 1-million-token context wind…

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