Meta Muse models explained: Muse Spark 1.3, 1.2, 1.1 and Glimmer, with release dates
Meta's frontier models stopped being called Llama in April, and the only Muse you can download so far is the small one.
The newest Meta model is Muse Spark 1.3, released on September 2, 2026. It's the fourth Muse Spark since April, and Meta's roadmap for it includes something the earlier ones never had: an open-weights release, not yet dated.
If you last looked at Meta's AI when it meant Llama, most of this is new. Meta's frontier work now comes out of Meta Superintelligence Labs under the Muse name, and the newest repositories in its Llama account on Hugging Face date from April 2025. I pieced the lineup below together from Meta's own launch posts, its developer pages and the Muse Glimmer model card, all read on September 23, 2026.
Every Muse release, by date
| Date (2026) | Release | What it is |
|---|---|---|
| Apr 8 | Muse Spark | First Muse model, in the Meta AI app |
| Jul 7 | Muse Image | Image generation, in Meta AI |
| Jul 9 | Muse Spark 1.1 | Model, plus the Meta Model API in public preview |
| Aug 5 | Muse Spark 1.2 | Coding-tuned model, plus Muse Code beta |
| Aug 10 | Muse Glimmer | 30B open-weight model, Apache 2.0 |
| Sep 2 | Muse Spark 1.3 | Current model |
| Sep 8 | Muse | Personal agent app, runs on Muse Spark |
| Not out | Muse Video | Previewed in July, "coming soon" |
Dates from Meta's launch posts on ai.meta.com, research.meta.ai, about.fb.com and its developer blog, read September 23, 2026.
Where Llama went
Muse Spark launched on April 8, 2026, and Meta was clear it was a break from what came before. Meta Superintelligence Labs says it spent nine months rebuilding its pre-training stack, and that the new recipe reaches the same capability with "over an order of magnitude less compute than our previous model, Llama 4 Maverick". Pre-training is the expensive first stage of building a model.
That first Muse Spark was built for Meta's own products. It went into the Meta AI app and website, with API access limited to a private preview for selected partners. Developers couldn't sign up until July.
Meta's developer site still carries Llama 4 docs, but every model it has launched since April carries the Muse name.
Muse Spark 1.1, 1.2 and 1.3
The version numbers here move fast, and the three are priced identically, which makes them easy to confuse.
Muse Spark 1.1, on July 9, was the one that opened the door to developers. Meta launched its Model API in public preview alongside it, with a million-token context window. Meta pitched it at agent work: planning a job, handing parts of it to subagents and operating a computer.
Muse Spark 1.2, on August 5, arrived with Muse Code, Meta's first coding agent, in early beta. Meta called 1.2 "a moderate improvement over Muse Spark 1.1", tuned for the jobs coding agents get most, like multi-file refactors and long debugging sessions. The same day, Meta widened its API preview to developers worldwide.
Muse Spark 1.3, on September 2, is the current one. Meta says it was trained on more long-running coding tasks, asks clarifying questions when a prompt is ambiguous and confirms before taking consequential actions. In comparisons by Meta's own engineers it used about 20% fewer tool calls and 25% fewer tokens than 1.2 on the same work. Fewer tokens at the same price is a real saving, if it holds up on your workload.
All three are still listed on the Model API at $1.25 per million input tokens, $0.15 for cached input and $4.25 for output. Meta still lists 1.1 and 1.2 beside 1.3, so there's no forced move yet.
How you call Muse Spark
There are three ways in. Meta's Model API is the direct one, and its page says you can point code written for the OpenAI SDK at it with a new key and address, which spares you a rewrite. Muse Spark is also on OpenRouter, the service that resells many labs' models behind one account. And Muse Code, Meta's terminal coding agent, installs with one command and runs on the same API.
The API can also search the web for you. Meta offers search grounding as a tool you add to a request (grounding meaning the answer is built from pages it fetched just then), which matters for anything that changed after the model was trained.
The contributor tier
This was the detail I didn't expect on a price list. Muse Spark 1.2 and 1.3 each come in a second version with -contributor on the end of the ID, priced at $0.10 in and $0.20 out, under a twentieth of the standard output rate. Meta's table marks those IDs "Used to improve our products" and the standard ones "Not used to improve our products".
So the cheap tier is cheap because your prompts help train Meta's models. That's a fair trade for a hobby project and a bad one for client code. Muse Code starts new users on the contributor tier, rate-limited by tokens over a rolling five-hour window, and Meta's 1.2 post says to swap the model ID to the standard one when you need more. We've gone through Muse Spark 1.3's limits in Cursor in another piece.
Muse Glimmer, the one you can download
Muse Glimmer came out on August 10, 2026 with its weights on Hugging Face under Apache 2.0, a license with no user or revenue conditions. It's a 30-billion-parameter model (29.6 billion, counting a 1.8-billion-parameter image encoder) that Meta says was distilled from Muse Spark, meaning trained to imitate the bigger model's answers.
Meta built it for agents that run entirely on your own machine. Its model card says a roughly 4-bit version of the language model fits under 20 GB, leaving room for the rest inside a 24 GB or 32 GB graphics card, and the full-precision version wants 64 GB. It reads 131,072 tokens and its knowledge stops at January 4, 2026.
It also ships with a small companion model for speculative decoding. The card says this drafter proposes 16 tokens at a time, and Meta measured the pair on M4 Max and M5 Max MacBooks and on an Nvidia RTX 5090. Ready-made GGUF and ExecuTorch versions sit beside the main repository, so llama.cpp users don't have to convert anything.
Note where it lives. The Hugging Face organization is meta-models, a new account, so searching Meta's old Llama account turns up nothing.
Muse Image, Muse Video and the Muse agent
Muse Image launched on July 7 inside Meta AI, Instagram and WhatsApp, and it's on the Model API at $0.01 an image. Muse Video was previewed in the same announcement and is still described as "coming soon to creators and Meta AI".
Then there's Muse with no second word. Launched on September 8, 2026, it's a personal agent app that runs on a dedicated virtual machine Meta calls Muse Secure VM, works in its own app or inside WhatsApp, and is powered by Muse Spark. We covered its arrival on the Mac separately.
Muse Spark 1.3's announcement ends with Meta's roadmap: "bigger models, the Muse Spark open weights release, and more."
Quick answers
What is the newest Muse Spark?
Muse Spark 1.3, released on September 2, 2026 on Meta's Model API and in its Muse Code coding tool. It costs $1.25 per million input tokens and $4.25 per million output.
Is Muse Spark open source?
Not yet. Meta's Muse Spark 1.3 post lists "the Muse Spark open weights release" on its roadmap, with no date. The only open-weight Muse today is Muse Glimmer, a 30-billion-parameter model under Apache 2.0.
Is there a Llama 5?
No. Meta's newest frontier models are the Muse line, which started with Muse Spark on April 8, 2026. The newest repositories in Meta's Llama account on Hugging Face date from April 2025.
What's the difference between Muse Spark 1.3 and 1.2?
Meta says 1.3 was trained on more long-horizon coding work, asks clarifying questions when a prompt is unclear, and in Meta's own comparisons used about 20% fewer tool calls and 25% fewer tokens than 1.2. The price is the same.
What is the Muse Spark contributor tier?
Model IDs ending in -contributor cost $0.10 in and $0.20 out per million tokens, and Meta's price table marks them "Used to improve our products". The standard IDs aren't. We've covered what the contributor tier costs you separately.
Is Muse the same as Muse Spark?
No. Muse Spark is the model. Muse, launched on September 8, 2026, is Meta's personal AI agent app, and it runs on Muse Spark.
More on Meta
- One undocumented Muse setting lets local malware redirect your dictation, and Patrick Wardle shipped the exploitSeptember 22, 2026
- Is Muse Spark 1.3 free on OpenCode, and what do you get for $10 a month?September 19, 2026
- Meta's Muse agent now reaches the files and messages on your Mac and acts on themSeptember 19, 2026