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Meta · Released Sep 2, 2026

Muse Spark 1.3

Muse Spark 1.3 is a multimodal reasoning model from Meta for long-running agentic, multi-agent, and coding workflows. It improves long-horizon agent collaboration, instruction following, and coding efficiency relative to Muse Spark 1.2.

  • Proprietary
  • Reasoning
  • Tool calling
  • Vision
  • Audio input
  • Video input
Capability
156.9ECI · #17 of 148
Input
$1.25per 1M tokens
Output
$4.25per 1M tokens
Context
1.05M131K max output
Pricing

What it costs

Input
$1.25per million tokens
Output
$4.25per million tokens
Cached input
$0.15per million tokens
Blended (3:1)
$2.00pricier than 70% of priced models

Typical monthly bills

Monthly usageEstimated cost
Side project2M input + 0.5M output tokens$4.63
Team assistant25M input + 5M output tokens$52.50
Production app250M input + 50M output tokens$525.00

Official Meta API price, as listed on models.dev.

Capability

Independent benchmarks

156.9Epoch Capabilities Index
#17 of 148 scored models
88Median 146167

The shaded band is Epoch AI’s confidence range (154.7–159.6); the tick marks the median scored model.

  • FrontierMath Tiers 1–3Research-level mathematics · xhigh setting74.4%
  • OTIS Mock AIME 2024–2025Competition mathematics · xhigh setting99.2%

Scores from Epoch AI, run independently of Meta.

Specifications

The details

Lab
Meta
Released
Sep 2, 2026
Context window
1,048,576 tokens
Max output
131,072 tokens
Inputs
Text, Images, PDFs, Audio, Video
Output
Text
Reasoning
Adjustable effort minimal · low · medium · high · xhigh · max
Tool calling
Yes
Structured output
Yes
Weights
Proprietary
API model ID
muse-spark-1.3on Meta
Availability
12 API providerslisted on models.dev

Meta model documentation

Lab-reported

What Meta claims

Published by the lab at launch. Settings vary, so compare these only with care.

BenchmarkScoreSettingSource
GDPval-AA v21754 Elomax effortSource
JobBench64.9max effortSource
OSWorld v2.066.9max effortSource
OSWorld v2.032 binary completion ratemax effortSource
DeepSearchQA90.3 F1max effortSource
Agentic IF Index57.8max effortSource
AutomationBench49.6max effortSource
MRCR v298.5 mean sequence-match ratiomax effortSource
MRCR v298.1 mean sequence-match ratiomax effortSource
DeepSWE v1.175.4max effortSource
SWE-Atlas Codebase QnA59.4max effortSource
Terminal-Bench v2.188.8max effortSource
Same lab

More from Meta

Questions

About Muse Spark 1.3

How much does Muse Spark 1.3 cost?

Muse Spark 1.3 costs $1.25 input / $4.25 output per million tokens (official Meta API price). Cached input is $0.15 per million tokens. At a 3:1 input-to-output mix that is $2.00 per million tokens, more expensive than 70% of the 360 priced models we track.

What is the context window of Muse Spark 1.3?

Muse Spark 1.3 accepts up to 1,048,576 tokens per request and can write up to 131,072 tokens in one response.

How good is Muse Spark 1.3?

Epoch AI gives Muse Spark 1.3 a Capabilities Index score of 156.9 (likely range 154.7–159.6), ranking it #17 of 148 models Epoch has scored. Epoch AI benchmark results: FrontierMath Tiers 1–3 74.4%, OTIS Mock AIME 2024–2025 99.2%.

Is Muse Spark 1.3 open source?

No. Muse Spark 1.3 is proprietary; you use it through Meta’s API or partner platforms.

What inputs does Muse Spark 1.3 support?

Muse Spark 1.3 accepts text, images, PDFs, audio and video and replies in text. It is a reasoning model with minimal, low, medium, high, xhigh and max effort settings, supports tool calling and can return structured JSON output.

When was Muse Spark 1.3 released?

Meta released Muse Spark 1.3 on Sep 2, 2026.

What are the best alternatives to Muse Spark 1.3?

The closest current models from other labs on capability, price and release date are Gemini 3.8 Flash (Google, ECI 156.9, $0.75 / $3.75), GLM-5.3 (Z.ai (Zhipu), ECI 155.8, $1.40 / $4.40), Grok 4.6 (xAI, ECI 156.6, $2.00 / $6.00) and Qwen3.8 Max (Alibaba (Qwen), ECI 156.6, $2.00 / $6.00).