Meta Muse vs Gemini Spark vs Grok Bot, Compared

Three companies shipped a personal AI agent within a month of each other. Meta’s Muse launched on 8 September 2026, xAI’s Grok Bot on 11 August 2026, and Google’s Gemini Spark is live for paying subscribers. Everything below is what each vendor says on its own page. None of it has been independently tested, here or anywhere this page could find.

What is Meta Muse?

Meta describes it plainly: “Muse is a personal AI agent. It doesn’t just answer questions, it actually does the work.” The part worth knowing is the design around it. A second agent, the Sentinel, sits between Muse and the internet: “A separate Sentinel agent runs on that same machine, kept apart from Muse at the system level”, and “Nothing Muse does reaches the internet unless the Sentinel approves it, and it asks the person for permission when needed.”Meta, Introducing Muse, 8 Sep 2026, read at source 16 Sep 2026.

Where you can use it: “Muse is rolling out in the US on iOS, Android, and muse.ai, and coming soon to AI glasses.” What it costs: “It’s free for most of what people need, with subscription plans for people who want to do more.” That launch post does not price the plans; Meta’s Help Center does, at $20 and $100 a month as of 22 Sep 2026, and a Mac app followed on 17 September 2026.Meta Help Center, About Muse subscriptions, read at source 22 Sep 2026: “Power plan ($20/month) 500M Muse tokens per week” and “Maximum plan ($100/month) 3B Muse tokens per week” · Meta, Muse download page, read at source 22 Sep 2026: “Muse for Mac OS, right on your desktop computer.” · Mark Zuckerberg, Threads post, 17 Sep 2026: “Muse for Mac is out today!” Until 22 Sep 2026 this paragraph said Meta did not publish the plan prices. Fuller explainer: what is Meta Muse.

What is Gemini Spark?

Google calls Spark “Your 24/7 personal AI agent for productivity”, and leans on the same always-working promise: “Give it a task and it works in the background 24/7, even if your phone and laptop are turned off.” On control, Google says it “operates autonomously, but always under your direction” and is “designed to check with you before taking major actions”.Google, Gemini Spark, read at source 16 Sep 2026. The product page carries no launch date; Google’s what’s-new page does: “May 19, 2026 — Initial launch: Gemini Spark starts rolling out with Schedules and Skills in the United States.” (read at source 22 Sep 2026).

Access is the sharpest difference: “currently available for Google AI Pro and Ultra subscribers over 18 in select countries”, plus “select business users”. Its help page is more specific: “Available wherever Gemini Apps are supported, except in the European Economic Area, Nigeria, Switzerland, and the United Kingdom.”Google, Gemini Spark help, read at source 22 Sep 2026. Google’s own small print is worth repeating in full: “Check responses. Supervise closely, interrupt when needed. Subscription required. Compatibility and availability vary. 18+.”

What is Grok Bot?

xAI describes Grok Bot in the plural: “Grok Bot is your team of always-on agents. They have their own computer, work inside tools and apps like you do, and keep working 24/7.” On what they do: “They sign into the tools you already use and work across apps, inboxes, and more”, and “They finish jobs end to end, and only come back when something needs your approval.”xAI, Introducing Grok Bot, 11 Aug 2026, read at source 16 Sep 2026.

It is not general release: “Grok Bot is in beta and available today for SuperGrok, SuperGrok Plus, and SuperGrok Heavy; Cursor Pro, Pro+, and Ultra; and Cursor Teams Standard and Premium subscribers on desktop and iOS.” If you are wondering which Grok this is, it is not the companion characters — see the three products that share these names.

How do they compare?

What has nobody shown yet?

Every line above is a vendor describing its own product. What is missing is the part that would let you choose between them:

• No independent test of any of the three was found. Not of task success, not of how often the approval step actually fires.
• No published failure rate. An agent that acts on your behalf will sometimes act wrongly; none of the three pages says how often.
• No launch date on Google’s Spark page.First-hand: until 22 Sep 2026 this item also said there was no price for Meta’s paid plans; Meta’s Help Center now lists them, quoted above.
• No stated limits on what each agent will refuse to do, beyond the approval language quoted above.

Until somebody measures them, the sensible reading is that these are three descriptions of an intention, shipped at three different stages of readiness.