Muse Spark 1.3 (Reasoning)
by Meta
Muse Spark 1.3 (Reasoning) is a reasoning model from Meta, released on September 2, 2026. It has a 1M-token context window and can generate up to 944K output tokens. API pricing is $1.25 per 1M input tokens and $4.25 per 1M output tokens. It ranks #8 of 220 models by Intelligence Score with a score of 52.8.
Muse Spark 1.3 is Meta Superintelligence Labs' proprietary multimodal reasoning model for long-running agentic, multi-agent, and coding workflows. It improves on Muse Spark 1.2 in long-horizon collaboration, multitasking, instruction following, tool use, failure recovery, and concise coding execution. It supports a 1,048,576-token context window and is available through Muse Code and the Meta Model API in standard and contributor tiers. ZeroEval routes to the lower-cost contributor endpoint, where prompts and outputs may be used to improve Meta's products, while standard pricing remains the default comparison basis.
Key specs
| Provider | Meta |
|---|---|
| Release date | 2026-09-02 |
| License | proprietary |
| Context window | 1M tokens |
| Max output | 944K tokens |
| Input price | $1.25 / 1M tokens |
| Output price | $4.25 / 1M tokens |
| Intelligence Score | 52.8 |
| Coding index | 40.3 |
| Output speed | 17 tokens/s |
| Time to first token | 2.64 s |
Quick answers
What is the context window of Muse Spark 1.3 (Reasoning)?
Muse Spark 1.3 (Reasoning) has a context window of 1M tokens, with a maximum output of 944K tokens per response.
How much does Muse Spark 1.3 (Reasoning) cost?
Muse Spark 1.3 (Reasoning) costs $1.25 per 1M input tokens and $4.25 per 1M output tokens through the API.
Is Muse Spark 1.3 (Reasoning) open source?
No. Muse Spark 1.3 (Reasoning) is a proprietary model from Meta (proprietary license).
When was Muse Spark 1.3 (Reasoning) released?
Meta released Muse Spark 1.3 (Reasoning) on September 2, 2026.
How does Muse Spark 1.3 (Reasoning) compare to Claude Opus 5.5 (Reasoning)?
Muse Spark 1.3 (Reasoning) scores 52.8 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $1.25 vs $4 per 1M tokens.
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