Switch your monitor's input from a Stream Deck key
To switch your monitor's input from a Stream Deck, add Monitor Input Keys for Windows and put one key per input (HDMI, DisplayPort, USB-C) on your Stream Deck. Press the key and the monitor changes input through the video cable over DDC/CI, so you don't open the monitor's on-screen menu and you need no extra hardware.
Get it on the Elgato Marketplace
The plugin sends the switch over DDC/CI, the control channel inside the video cable that most desktop monitors have.
Get Monitor Input Keys for Windows on the Elgato Marketplace
Add a Switch Input key, choose the monitor and set Switch to DisplayPort 1 (or the port you use). Press the key, then press again within 3 seconds, and the monitor changes input. Make one key for each input you use, or one Cycle Inputs key that steps through them.
No. It uses DDC/CI, the control channel in your normal video cable. If DDC/CI is off, turn it on in the monitor's own on-screen menu (sometimes under Other, System or Setup).
Yes, while this PC can still see the monitor. Over HDMI many monitors stay visible, so a second key switches back. Over DisplayPort and USB-C the monitor usually disconnects from this PC, so switch back from the other device or with the monitor's buttons.
Yes. Each key switches one monitor, which you choose from a list in the key's settings.
Yes. Choose Other and enter the input code (the value of VCP code 0x60). The Status line in the key's settings shows the inputs the monitor itself reports.
No. It writes only the input setting (VCP code 0x60).