Meta Ships Muse Spark 1.3, Calling It the Biggest Jump Since Spark Launched
On September 2, 2026, Meta Superintelligence Labs released Muse Spark 1.3 in Muse Code and the Model API—about 20% fewer tool calls and 25% fewer tokens than 1.2 on internal coding, with Artificial Analysis Intelligence 61 at xhigh versus Fable 5.1 max at 66.
TLDR
Meta Superintelligence Labs on Wednesday, September 2, 2026 published Muse Spark 1.3—fourth Spark in five months—live in Muse Code and the Meta Model API. Existing reasoning modes at launch; max held for extra safety testing (max GA September 4—footnote, not a second article). Yuandong Tian / Wang to Bloomberg: “biggest jump so far,” “competitive” with Fable 5.1, “better than” GPT‑5.6 Sol on coding. Zuckerberg: “frontier performance almost too cheap to meter”; Watermelon + open weights still on the roadmap, no date. Meta-internal coding: ~20% fewer tool calls, ~25% fewer tokens vs 1.2. Artificial Analysis Intelligence Index: 1.3 xhigh 61, 1.3 max (preview) 62; Fable 5.1 max 66. Meta chart: DeepSWE v1.1 75.4%.
Ranking context
| Source | Spark 1.3 | Peer |
|---|---|---|
| AA Intelligence (launch window) | 61 xhigh / 62 max preview | Fable 5.1 max 66 |
| Meta DeepSWE v1.1 | 75.4% | lab chart |
| LMArena | Check live board; do not invent Elo | — |
Product-line de-dupe: not Aug 5 Spark 1.2 / Muse Code, not Aug 10 Glimmer, not Sep 8 Muse consumer agent.
Why this story matters
Meta is iterating Spark on a monthly clock and talking price-to-meter. Watch: Watermelon weights, and whether AA 61 closes on Fable 5.1 after max GA.