Meta put two apps on the Mac a month apart, gave them overlapping names, and ran both on the same model. Nearly everyone assumes Muse is the newer, better Meta AI. It is not an upgrade it is a different shape of tool, and one asymmetry explains every difference between them: a wrong answer is something you read, a wrong action is something already done.
Meta AI for Mac arrived on August 19, 2026 and answers questions, including about a window you hand it. Muse arrived on the Mac on September 17 and carries out multi-step work inside your apps. Neither is a newer edition of the other, they install separately, and plenty of people run both. If you remember one sentence, make it this one: if you want to know something, that is Meta AI; if you want something done, that is Muse.
A desktop assistant that sits above everything else, summoned with a keystroke. It can look at one window you point it at and reply about it and it can type for you through dictation, but only where your cursor already is.
An agent that works inside your apps while you do something else: organising files, filling in forms, pulling from Messages, Calendar and Notes. Meta says it confirms before anything sensitive and that its work runs in a sandbox it calls the Muse Secure VM.
Most comparisons of these two stop at a feature list, which makes them look like near neighbours with a couple of extra boxes ticked. They are not. The gap is one of kind, and it shows up most clearly in what happens when the model gets something wrong.
When Meta AI misreads your spreadsheet, you read a wrong answer and discard it. The cost is a few seconds and a little irritation. Your Mac is exactly as it was.
When Muse misreads the same spreadsheet, it has already moved the files. The cost is whatever undoing that takes and unlike a bad paragraph, you may not notice for a week.
Same model, same mistake, completely different consequence. That asymmetry is not a footnote about risk. It is the reason the two products are shaped the way they are.
Work backwards from it and the rest of this page stops being a list and starts being a consequence. Muse asks for permission per area because it changes things in those areas. It confirms before sensitive steps because an unconfirmed send cannot be unsent. It meters in tasks rather than messages because a task is work performed, not text returned. It launched in one country because acting on someone’s behalf raises questions that answering a question does not. Meta AI needs none of that, which is why it reached most of the world in August while the agent was still in one market in September.
It also explains the habit that separates people who get value from an agent from people who get burned by one: read the plan before it runs, not the result after. With a chat assistant, checking afterwards is fine. With an agent, afterwards is too late to be checking.
The two highlighted rows are the ones that decide it for most people. The rest is detail worth having once you have chosen.
| Meta AI for Mac | Muse for Mac | |
|---|---|---|
| Core verb | Reads Answers questions, drafts, summarises, explains. | Acts Carries out multi-step work inside your apps. |
| Where it is available | Broad rollout Check your country. | United States only at launch, expanding. Why. |
| Released on Mac | August 19, 2026 | September 17, 2026 nine days after the iPhone release |
| How you invoke it | ⌥Space opens a compact chat over whatever you are doing. Shortcuts. | You describe an outcome and it plans the steps. How to phrase one. |
| What it can see | One window you attach its visible text plus a screenshot. Not a live feed. Window sharing. | The areas you have granted, app by app, for as long as the task needs them. |
| What it can change | Nothing. It replies; your files and apps are untouched. | Files, forms, and content in Messages, Calendar, Notes and Mail. |
| Permissions it asks for | Screen Recording and Accessibility, for window attachment. What each grants. | Per-area access you grant individually, with a confirmation before anything sensitive. |
| What a mistake costs | A wrong answer you read and discard. | A wrong action already taken. Why this matters most. |
| How the free tier meters | Generation images, video and other heavy features. Pricing. | Tasks, on a weekly allowance, where a task is a variable-cost unit. Pricing. |
| Dictation into other apps | Yes System-wide, types wherever your cursor is. Guide. | Not its job It acts on outcomes rather than transcribing you. |
| Model underneath | Muse Spark 1.3 for both, since September 2, 2026 a one-million-token context window, stronger tool-use benchmarks, and a slight regression on long-document accuracy. | |
| Read next | How to use Meta AI for Mac | Getting started with Muse |
Claims about sandboxing and confirmation prompts are Meta’s own and are reported here as such. What Meta says about the Secure VM.
Worth stating plainly, because the naming invites people to assume one supersedes the other. It does not.
What they do not share: availability, permissions, the unit they meter, and what happens when they are wrong. Those four are the whole comparison.
A working rule: if the output is something you will read, that is Meta AI. If the output is a change to your Mac, that is Muse.
| What you want | Reach for |
|---|---|
| “What changed between these two versions of the spreadsheet?” | Meta AI |
| “Tighten this paragraph and make it less pompous.” | Meta AI |
| “Explain what this error on screen means.” | Meta AI |
| “Type this out while I talk.” | Meta AI |
| “Sort last month’s receipts into folders by month.” | Muse |
| “Pull the dates out of these emails and put them in my calendar.” | Muse |
| “Fill in this form from the details in that document.” | Muse |
| “Rename these two hundred files to a consistent pattern.” | Muse |
Notice the pattern in the Muse rows: every one of them is tedious rather than difficult. That is the honest description of what an agent is good at, and it is a more useful guide than any feature list.
People who run both settle into the same rhythm fairly quickly: think in one, execute in the other.
Hand it the window and ask what is actually in front of you. Understanding the job is cheap here and expensive in an agent. Attaching a window.
Ask it to turn what you just learned into a precise instruction: which folder, which dates, what to leave alone.
A task that names its scope is a task that runs in three steps rather than thirty better results and less of your weekly allowance. Why scope is cheap.
The moment to correct an agent is before it starts. Afterwards you are not reviewing, you are repairing.
Point it at the folder or the draft Muse produced and ask whether it looks right. The reader checking the doer is a decent arrangement.
If Muse has not reached your country, steps one, two and five still stand on their own which is most of the value, and it is available today. Where Muse works.
Meta AI reads and Muse acts. Meta AI for Mac looks at a window you hand it and answers questions about it; Muse works inside your apps organising files, filling in forms, pulling from Messages, Calendar and Notes. They are separate downloads, not two versions of one product.
No, and this is the commonest misreading. They run on the same model Muse Spark 1.3 and neither is a newer edition of the other. They are different shapes of tool for different jobs, and most people who use both keep both. What they share.
Most people want Meta AI first, because questions, drafting and summarising are the bulk of everyday use and it is available far more widely. Add Muse when you have work that is tedious rather than difficult, and you are somewhere it has rolled out. Which job goes where.
Because it acts rather than reads. Meta AI asks for Screen Recording and Accessibility so it can see one window you point at; Muse asks per area files, mail, calendar, messages because those are the things it will change, and Meta says it confirms before anything sensitive. How the grants work.
Yes. Muse Spark 1.3 has been the engine since September 2, 2026, with a one-million-token context window. The difference between the products is what each is permitted to do with it, not how clever each one is.
Yes system-wide dictation, which types into whichever app has focus, is a Meta AI feature and the one most people end up keeping. Meta AI is also available in far more countries, which for most readers is the decisive difference.
Muse, necessarily. A wrong answer from a chat assistant is something you read and discard; a wrong action from an agent has already happened. That asymmetry is why it asks before sensitive steps and why its first rollout was deliberately narrow. The full argument.
Both have free tiers, but they meter different things. Meta AI meters generation images, video and other heavy features. Muse meters tasks on a weekly allowance, and a task is a variable-cost unit whose size you largely control. How that works.
No. Meta AI had a broad rollout; Muse launched in the United States only, on iPhone from September 8, 2026 and the Mac from September 17. For most readers outside the US this settles the comparison before any feature does. The five gates.
They are separate apps signed into the same Meta account, and each states its own handling. Meta says Muse’s work happens in a sandbox it calls the Muse Secure VM, kept out of its advertising systems. Read Meta AI’s and Muse’s own pages rather than assuming one covers the other.
Meta AI if you want an answer. Muse if you want the work carried out and, in most of the world, Meta AI is the one you can have today.
Independent guide not affiliated with Meta. Dates and behaviour described here are as of September 2026; statements about Meta’s sandboxing and confirmation prompts are Meta’s own. Muse is US-only at launch.