Share windows
between your Macs.

Screen sharing shows you a whole desktop inside a window, so you end up working in a window within a window. Beam gives you the window itself. It sits on your desktop at its own size, with its own Dock icon, in your ⌘ Tab.

No, and they solve different problems. Universal Control shares one keyboard and mouse between Macs sitting side by side. Beam brings a window from a Mac in another room, or another building, onto the one in front of you.

No. Your Macs talk to each other directly, over your own network at home and over your tailnet when you are apart. There is no account to make and nothing to relay through, so nobody else is ever in the path.

The first time you pick a Mac, Beam asks you to pair. The Mac you are reaching for shows a one-time code when you choose Pair a Mac from its menu bar, or you can give it a Beam password once and type that instead, which is handy for a Mac with no screen. Either way the two Macs end up trusting each other by key, nothing is shared or uploaded, and you can remove a paired Mac from Settings at any time. Being on the same network is never enough on its own.

Two Macs on macOS Sonoma or later, with Beam installed on both. Being on the same network is enough on its own; Tailscale is optional and only earns its keep when the Macs are apart. The Mac doing the sharing grants Screen Recording and Accessibility once.

Only what you pick. You beam one window at a time, or a whole display if you choose one. Hidden apps and password managers never reach the list at all, and you can stop any share from the menu bar.

Yes. Beam prints a link that opens that one window in any browser, on any device. It is view only unless you say otherwise, and it expires after an hour.

Yes, and that is half the point. A headless Mac mini or Studio running builds or agents lists its windows like any other Mac, and there is a command line and a doctor for setting one up over SSH.