Muse Spark Open

Verdict: Meta open-weight release of its Muse Spark model: an 816B mixture-of-experts with 42B active params, billed as the most capable US open-weight model to date.

Use this if you want a frontier-class open model to self-host for agentic work, for example on an M5 Ultra Mac Studio.

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Visit Muse Spark Open →

Live X Buzz Score

🔥 59/100 Hype updated 16 Oct, 01:43 HKT

550posts, last 24h

2,044posts, last 7 days

2.21×24h vs prior daily avg (249)

181likes in top 24 sampled posts

Daily X posts, last 7 days (oldest → today): 117 · 86 · 81 · 154 · 826 · 230 · 550. Score parts: volume 33.1/50, spike 14.3/25, engagement 11.9/25. Method

Why it's buzzing

@AIatMeta · 2026-10-15

Today we’re releasing Muse Spark Open, the most capable US open-weight model to date. Built for coding and agentic work, it excels at long-horizon tasks, complex software engineering, and multi-step reasoning. Key Model Specs: → 816B total / 42B active parameters → 1M token htt

♥ 3,385 · ⟲ 349 · 💬 157 · 👁 124k

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ChatGPT: The default general assistant; strong all-rounder with a huge plugin and GPT ecosystem.

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FAQ

What is Muse Spark Open?

Meta open-weight release of its Muse Spark model: an 816B mixture-of-experts with 42B active params, billed as the most capable US open-weight model to date.

Who should use Muse Spark Open?

Use Muse Spark Open if you want a frontier-class open model to self-host for agentic work, for example on an M5 Ultra Mac Studio.

Is Muse Spark Open free?

Muse Spark Open is listed as open-source.

What are alternatives to Muse Spark Open?

Alternatives include NVIDIA Nemotron 3.5, ChatGPT, OpenCode 2.0, Claude Code.

Discussion

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