How do I disconnect a screen or hand a monitor to another computer?

How do I hand off an external monitor?

1. Keep another physical screen active on the Mac.
2. Open Radar Display's menu bar panel and identify the monitor under Displays.
3. Turn that monitor's connection switch off. Wait for the progress indicator to finish.
4. Use the monitor's own input controls to select the other computer or console.

The switch removes the display from the Mac's desktop. Radar Display does not choose the monitor's HDMI or DisplayPort input. A monitor that automatically changes input when the Mac's signal stops may switch by itself; this is the monitor's behavior.

To return the monitor to the Mac:

1. Select the Mac's input on the monitor.
2. Open Radar Display and turn that monitor's connection switch on.
3. Wait for it to rejoin the desktop. Expand its row if you need to check its arrangement or display settings.

When a monitor remains detectable while showing another input, its row can stay in Radar Display. The switch records your requested connection state; the monitor's visible picture also depends on its selected input and the connection succeeding.

If macOS refuses the change, Radar Display shows an error beneath that display and restores the switch's previous request. Read the error before retrying.

Can I turn off the MacBook screen?

Yes. With another physical display active, turn off the built-in display's switch. Turn it on again to use the MacBook screen. Keep the lid open if you want that screen available; macOS controls the built-in panel while the lid is closed.

Radar Display disables the disconnect switch for the last active physical display and marks it Only active display. An iPad Sidecar session does not count as the spare physical display for this protection. A mirrored secondary screen may also be excluded from the active-display count.

For example, a MacBook with one working external display can turn off its built-in screen. If the external screen is unavailable and the built-in screen is the only active physical display, the built-in switch is disabled.

The app also attempts to reconnect the built-in screen when no usable physical display remains. Closed-lid policies still apply, so open the MacBook lid as part of recovery.

What happens when a cable or monitor returns?

Radar Display remembers each recognized physical display's requested on/off state. A monitor you switched off can return with that request still off. A monitor you left on can be reconnected when it becomes available again.

Unplugged or undetectable monitors are hidden from the panel; their saved records are retained. Reopening the panel refreshes the current display list. A sleeping display is not automatically treated as an unplugged display.

Matching depends on identifiers provided by the display and macOS. Two identical monitors without distinct usable identifiers cannot always be matched to their old records. A custom name helps you read the list but does not create a hardware identifier. See remembered settings.

What does Connection tell me?

Expand an on display and look for Connection. The app can report Internal, HDMI, DisplayPort, Wi-Fi, or USB, when it can determine the connection.

This row describes the detected display connection. It is not a monitor-input selector. A monitor connected through a USB-C cable can report DisplayPort because that is the display signal carried by the cable. For an iPad, Wi-Fi or USB describes the current Sidecar session; merely attaching a cable does not prove the active session uses USB.

Radar Display omits the row when it cannot identify the connection reliably.

Does quitting reconnect my screens?

Use Quit Radar Display from the icon's right-click menu for a normal quit. Radar Display attempts to reconnect present physical screens that it disabled and to release its sleep prevention. Restoration has a limited time to finish and can fail if macOS refuses the change.

Quitting does not erase saved on/off requests. If you relaunch, a saved off request can be applied again. It also does not undo resolution, rotation, HDR, or color changes, and it does not end an iPad Sidecar session.

A force quit or crash skips the normal restoration path. Do not rely on quitting alone to recover every screen. To recover:

1. Open the MacBook lid, if there is one.
2. Put the monitor on the Mac's input and check its cable and power.
3. Open Radar Display again from a working screen and turn the affected display on.
4. If the display is still missing, follow missing displays and controls.