Can a Stream Deck or similar controller switch my monitor’s input?

Yes, if the button device’s software can send a keyboard shortcut or run a BetterDisplay command. First make sure the desired input works in BetterDisplay’s Input Source menu. The monitor and connection need to support that change before you assign it to a button.

You can assign an input-source keyboard shortcut in BetterDisplay and configure the controller button to send that key combination. Alternatively, use a command-running action with the configured input’s identifier:

betterdisplaycli get -name="Desk Display" -inputSourceList
betterdisplaycli perform -name="Desk Display" -changeInputSource="INPUT_ID"

Replace the display name and INPUT_ID with your own display and an entry returned by the first command. If the button software cannot find the CLI, configure its command with the executable’s installed path. See the CLI examples for controller selection and alternate input commands.

For a complete six-key setup using native Apple Shortcuts and separate return requests, follow Build an Elgato Stream Deck control panel for your display setup.

The button setup depends on its software. After switching inputs, the monitor may stop accepting commands from that Mac. Test switching back before using the button for both directions. See switching an input back.