When a shared Mac window disappears

You are at your desk on Tuesday, working in a window beamed over from the Mac in the other room. You minimize it to clear some space, then pause when it disappears. The direct answer is simple: minimizing, hiding, or moving the source window to another Space keeps the same window alive. Closing it normally ends the shared view.

Beam puts a window from one Mac onto another: the window itself, on your desktop, at its own size, with its own Dock icon and a place in ⌘ Tab. A beamed window is a live view of the window you chose. It is not a snapshot of whichever pixels happen to occupy part of a display.

Traditional screen sharing starts with a display. Beam starts with one window. That source window can leave sight without ceasing to exist, or an app can replace it with a new window that looks almost identical. We wrote this post because those events can look alike while meaning very different things for the connection.

Start with the window you picked

Both Macs run Beam. They talk directly over the local network, or over your Tailscale tailnet when apart. No account, no server, no cloud. A tailnet is the private network Tailscale creates between your devices.

On the same network, Beam discovers other Macs running Beam locally, without asking anything outside the network. Pair them once and the connection is encrypted and pinned to those two machines. You then choose a source window in the picker and work with the beamed window on the Mac in front of you. Beam requires macOS Sonoma or later on both Macs.

When you beam a window, the picture, your keyboard and mouse input, and the clipboard if you have clipboard sync on, go straight from one of your Macs to the other. The connection begins with the particular window you selected, which is why its identity matters after it disappears from the source Mac’s current desktop.

The picture is streamed at your display’s exact resolution, so text stays crisp. A headless Mac gets a virtual display from Beam at Retina density. A virtual display gives a Mac without a connected monitor a desktop where its windows can appear. We keep the workflow centered on the selected window, whether its Mac has a physical display or not.

Minimize the window or hide the app

Minimize affects one window. It sends that window to the Dock without closing it, and restoring it brings the same window back. Hide works at the app level instead. Pressing ⌘H makes all of the current app’s windows disappear until you show the app again, while ⌘W closes one window and ⌘Q quits the app.

A minimized source window still exists. It has temporarily left the desktop for the Dock, but it has not been replaced or ended. Beam keeps the beamed window available, and you can restore the source window when you want to see it on the other Mac again. Your work remains attached to that same window.

A hidden app follows the same principle at a larger scope. Every window belonging to the app leaves view together, yet those windows remain open. Show the app again and its existing windows return. Beam keeps the selected window available while the app is hidden, so hiding changes what is visible rather than which window you selected.

The green window control belongs to another set of actions. It handles full screen, tiling, and related arrangements, separately from closing and minimizing. We treat these controls according to what happens to the selected window: moving or arranging it preserves the window, while closing it ends that particular window.

Moving it is not closing it

A Space is a macOS desktop. Moving a source window between Spaces changes which desktop displays it, but the same window remains open. If the other Mac is showing a different Space, the source may seem to have vanished even though it still exists on another desktop and remains the window you selected.

Deleting a Space does not close the open windows inside it. macOS moves those windows to another Space, and a beamed window remains available as its source moves with them. The location has changed, but the window has not. This follows the same pattern as minimizing and hiding: visibility can change while identity stays fixed.

Closing is the action that normally ends the shared view. Pressing ⌘W ends one window without necessarily ending its app. The app can remain open and continue running after that window is gone, but restoring is no longer possible because there is no longer an existing window to restore.

Quitting reaches further. Pressing ⌘Q ends the app, including its open windows. We can therefore follow the scope from smallest to largest: minimizing changes the location of one window, hiding changes the visibility of an app’s windows, closing ends one window, and quitting ends the app. The selected window survives only the actions that leave it open.

Do not mistake a replacement for a return

An app can show familiar content after an earlier window has closed, but familiar content does not establish that the old window returned. Slack can close a window, reopen familiar content in another window, or quit the app. A reopened Slack window may resemble the old one closely while still being a newly created window.

VS Code can behave the same way. You might close a project window and later open the same project again, with the same files and arrangement visible. The content makes the new window feel familiar, but it does not turn that window into the one that closed. In most cases, the earlier shared view ends with the original window.

Beam preserves a beamed window through minimizing, hiding, and moves between Spaces. Slack and VS Code can reopen familiar content in a new window, which is why reopening and restoring are separate operations. After an app opens familiar content again, you will usually see a new window rather than a continuation of the earlier shared view.

The next time a beamed window leaves view, look at the action that preceded it. Restore it from the Dock, show its app, or find its Space when the same window remains open. If it was closed, a newly opened window will usually appear separately, ready for you to beam as you carry your work forward.