Should I use a virtual screen or an HDMI dummy plug?

Use a virtual screen when you want a software-created desktop with configurable modes and no occupied video port. An HDMI dummy plug can be an alternative when you have a spare port and its advertised resolution choices meet your needs. Neither choice is guaranteed to be more stable in every setup.

A virtual screen gives you a desktop that other apps can capture, and BetterDisplay can mirror or stream its image to a physical display. You can configure its dimensions, modes and associations. A dummy plug instead presents a display connection through the Mac’s physical output, so its available modes depend on the plug and the Mac’s display-output capabilities.

For a remote-access workspace, follow Give a headless Mac a comfortable virtual desktop for remote access. The procedure keeps a saved desktop connected and checks display selection, input and reconnection in Apple Screen Sharing.

To keep apps on a desktop while its physical monitor is unplugged, keep a virtual screen connected and use it as the desktop source, mirrored or streamed to that monitor. Disconnecting the viewing monitor then leaves the virtual desktop available. Check the virtual screen’s association settings so removing its physical partner does not also disconnect the virtual screen.

This does not keep the physical output continuously connected. Creating a replacement virtual screen with the same vendor, model and serial information also does not guarantee the same macOS display ID or uninterrupted placement for every app. If your workflow specifically requires the physical connection to remain present, check whether a hardware EDID emulator meets that requirement. A software virtual screen is a separate display.

For a fixed desktop setup, a suitable plug may avoid some virtual-display compatibility problems. That is a reason to test it, not a promise that it resolves every sleep, wake, capture or pointer issue. Compare the resolutions you need and your actual remote-access or recording workflow, including reconnecting and waking the Mac.

Creating and connecting a BetterDisplay virtual screen from Pre-configured settings (recommended) does not require Pro. BetterDisplay’s mirroring, streaming and Picture in Picture features do require Pro. See virtual screens and presentation methods and licensing for the relevant distinctions.