Overview
Muse Spark is a Meta model. It was built by Meta Superintelligence Labs (MSL) and released on April 8, 2026 — announced the same day on the AI at Meta blog under the title "Introducing Muse Spark: Scaling Towards Personal Superintelligence" and on the Meta Newsroom as "Meta's Most Powerful Model Yet."
Meta describes it as "the first in a new series of large language models built by Meta Superintelligence Labs," and technically as a natively multimodal reasoning model with support for tool use, visual chain of thought, and multi-agent orchestration.
The strategic significance is larger than the model. Muse Spark is closed-weights — a deliberate break from the open-weight lineage that defined Llama. Meta has said it "hope[s] to open-source future versions of the model," language that concedes this one is not open. For a company whose AI identity was built on releasing downloadable weights, shipping a proprietary frontier flagship is the story.
Muse Spark supersedes Llama 4 as Meta's frontier model. Llama continues as Meta's open-weight family; Muse is now where Meta puts its best.
Capabilities
- Native multimodality — Meta describes Muse Spark as a "natively multimodal reasoning model," not a language model with vision bolted on. Meta cites complex reasoning across science, math, and health domains, with strong multimodal perception.
- Visual chain of thought — the model reasons through visual input step by step. See chain-of-thought reasoning for the underlying technique.
- Tool use — first-class support, rather than a wrapper behaviour.
- Multi-agent orchestration — the architectural feature that Contemplating mode exposes to users.
- Contemplating mode — Meta's reasoning mode, which "orchestrates multiple agents that reason in parallel." Meta rolled it out gradually to meta.ai after launch. Muse Spark's headline benchmark results are Contemplating-mode results.
- Pretraining efficiency — Meta claims it can "reach the same capabilities with over an order of magnitude less compute" compared with Llama 4 Maverick, and that Muse Spark is "significantly more efficient than the leading base models."
That last point is the most consequential technical claim Meta makes. A greater-than-10x reduction in the compute needed to reach a given capability level is a statement about Meta's pretraining recipe, not about Muse Spark's ceiling.
Technical Specifications
Meta has published very little conventional specification for Muse Spark. We list only what Meta has stated.
- Developer: Meta Superintelligence Labs (MSL), part of Meta
- Model type: natively multimodal reasoning model
- Reasoning: Contemplating mode, orchestrating multiple agents reasoning in parallel
- Supported: tool use, visual chain of thought, multi-agent orchestration
- Weights: closed. No download, no self-hosting.
- Architecture: Not disclosed. Meta has not published a parameter count, layer configuration, or whether the model uses a mixture-of-experts design.
- Context window: Not published by Meta. A 262,144-token figure appears on aggregator sites with no Meta source behind it; we do not report it.
- Knowledge cutoff: Not published by Meta.
- Pricing: Not disclosed.
The absence of a published context window is genuine, not an oversight on our part. Meta's launch materials are written for a consumer and partner audience, and the company has not released a model card with the specifications a developer would expect.
Use Cases
- Complex reasoning in science, math, and health — the three domains Meta names explicitly.
- Research-grade question answering — the FrontierScience Research and Humanity's Last Exam results position the model against hard, expert-level questions.
- Visual reasoning tasks — problems where the reasoning must run through an image, not merely start from one.
- Tool-augmented workflows — where the model must call out to external capabilities mid-reasoning.
- Parallel multi-agent problem solving — Contemplating mode's native shape: decompose, reason in parallel, reconcile.
- Consumer assistant — the model is free at meta.ai and in the Meta AI app, and rolls out across Meta's messaging surfaces and AI glasses.
Performance / Benchmarks
All figures are Meta-reported, from the Muse Spark launch materials, and all are Contemplating-mode results.
| Benchmark | Muse Spark (Contemplating mode) |
|---|---|
| Humanity's Last Exam | 58% |
| FrontierScience Research | 38% |
Compute efficiency: Meta claims it can "reach the same capabilities with over an order of magnitude less compute" than Llama 4 Maverick, and that Muse Spark is "significantly more efficient than the leading base models."
Meta has not published results on standard developer benchmarks such as SWE-bench, MMLU, or GPQA, and has not released a comparison table against competing frontier models. Independent evaluation is limited by the fact that API access remains in private preview.
Limitations
- No open weights. For a Meta model this is the defining constraint. No self-hosting, no fine-tuning, no offline deployment, no inspection. Meta hopes to open-source future versions; it has not committed to it.
- No API for most developers. Access is a private preview limited to select partners. There is no self-serve route and no published pricing.
- No published specifications. No context window, no parameter count, no knowledge cutoff, no architecture disclosure, no model card.
- Narrow benchmark disclosure. Two benchmark numbers, both in Contemplating mode. Nothing on coding, nothing on standard academic suites, no head-to-head comparison table.
- Little independent verification. Because API access is gated, third-party evaluation of Meta's claims is scarce.
- Contemplating mode rolled out gradually. The mode behind the headline numbers was not available to all meta.ai users at launch.
- Consumer-first framing. The launch materials address consumers and partners, not developers. Anyone planning an integration is working with incomplete information.
Pricing & Access
Meta has not disclosed pricing for Muse Spark.
- Free consumer access — available now at meta.ai and in the Meta AI app.
- API — private preview only. At launch Meta stated: "It will be available in private preview via API to select partners." No public terms, no self-serve signup, no published rate card.
- Meta's apps — rolling out to WhatsApp, Instagram, Facebook, and Messenger.
- AI glasses — rolling out to Ray-Ban Meta and Oakley Meta AI glasses, with Meta Ray-Ban Display slated for summer 2026.
Ecosystem & Tools
Muse Spark anchors an expanding Muse line. On July 7, 2026 — three months after Muse Spark — Meta launched Muse Image and previewed Muse Video, described as the first media generation models developed by Meta Superintelligence Labs.
- Muse Image — Meta's image generation model. Rather than mapping prompts directly to images, it operates as an agent: it invokes search and coding tools to improve accuracy, self-refines its generations, and improves through scaling test-time compute. It integrates with Muse Spark, draws on Instagram for social context, and embeds Content Seal, an invisible watermarking system for verifying AI-generated images. Meta reports it holds the No. 2 spot on Arena for text-to-image, single-image editing, and multi-image editing by human-preference Elo. Available in the Meta AI app, on meta.ai, in Instagram Stories in the US, and on WhatsApp in limited countries.
- Muse Video — built on the same pretraining base as Muse Image, with native audio support. Meta reports No. 3 in human-preference Elo for text-to-video. Coming soon to creators and Meta AI.
- Llama 4 — Meta's open-weight family. Muse Spark supersedes it as the frontier flagship, while Llama continues to serve open deployment.
- meta.ai — the free consumer surface for Muse Spark.
- Meta AI app — the mobile client, and where Contemplating mode rolled out.
Community & Resources
- Introducing Muse Spark: Scaling Towards Personal Superintelligence — the AI at Meta launch post
- Introducing Muse Spark: Meta's Most Powerful Model Yet — the Meta Newsroom announcement
- Introducing Muse Image and Muse Video — the July 7, 2026 media model launch
- Stay updated on Muse Spark — Meta's signup for Muse Spark news
- AI at Meta blog — Meta's research and release announcements
- meta.ai — try Muse Spark for free