Meta LLM Medium Closed weights

Muse Spark 1.3

71 days since Meta announced it · 2 Sep 2026

Muse Spark 1.3 is a closed-weights LLM from Meta, announced 2 Sep 2026. It costs $1.25 per 1M input tokens and $4.25 per 1M output tokens. Its context window is 1M tokens.

Input: $1.25; per 1M tokens
Cache write: —; per 1M tokens
Cache read: $0.15; per 1M tokens
Output: $4.25; per 1M tokens
Context window: 1M; tokens
Parameters: —; not disclosed

Announcement: research.meta.ai/blog/introducing-muse-spark-1-3
Docs: dev.meta.ai/models/muse-spark

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Meta · Medium

closed weights

A new one every ~28 days — due now.

Muse Spark 1.3 +28d 2 Sep 2026
Muse Spark 1.2 +27d 5 Aug 2026
Muse Spark 1.1 +92d 9 Jul 2026
Muse Spark 8 Apr 2026