# Muse Spark 1.3 Improves Coding Efficiency; Launch Index Trails Fable 5.1

Times of AI Desk · 2026-09-02 · Models

[https://timesof.ai/2026/09/meta-muse-spark-1-3](https://timesof.ai/2026/09/meta-muse-spark-1-3)

> Meta Superintelligence Labs released Muse Spark 1.3 — about 20% fewer tool calls and 25% fewer tokens than 1.2 on internal coding. Artificial Analysis Intelligence 61 at xhigh versus Fable 5.1 max at 66. Fourth Spark in five months.

**Meta Superintelligence Labs** released **Muse Spark 1.3** on September 2 for Muse Code and the Meta Model API. Meta’s internal coding comparisons report roughly **20% fewer tool calls** and **25% fewer tokens** than Spark 1.2.

## Claims and independent checks

Artificial Analysis’s dated September 2 evaluation describes the fourth Spark release in five months. It measured **61** on its Intelligence Index for **xhigh**, while **max**, then in limited partner preview, scored **62**. **Claude Fable 5.1 max** scored **66** in that comparison.

Those index results are separate from Meta’s internal coding-efficiency tests. Artificial Analysis also measured $0.55 per index task for xhigh at $1.25/$4.25 per million input/output tokens; it said max pricing was not yet public.

## Availability caveat

Meta’s current launch page says max reasoning is available. The dated Artificial Analysis report establishes its limited-preview status at launch, but the inspected pages do not establish September 4 as the exact general-availability date. Meta lists an open-weight release on its roadmap without a date.

**Correction (October 14, 2026):** Removed unsupported launch-day executive quotes and the unverified September 4 max-availability date; distinguished the current company page from the dated launch evaluation.

## Sources

- [Meta: Muse Spark 1.3](https://research.meta.ai/blog/introducing-muse-spark-1-3)
- [Artificial Analysis: September 2 Spark 1.3 evaluation](https://artificialanalysis.ai/articles/muse-spark-1-3)