Guide · 2 min read
On the Mac mini, turn on Screen Sharing, stop it sleeping when the display is off, and turn on Wake for network access; then connect from your MacBook. Wormhole has not yet been tested on a mini with no display attached; if it says there is no display, an HDMI dummy plug gives macOS one.
A headless Mac mini is one with no display, keyboard or mouse: it sits on a shelf or in a closet, and you use it from the Mac in front of you. The settings below are easiest to change while a display is still attached, so set them before you unplug it. Every macOS setting here comes from Apple's own support pages, listed under the post.
How do I reach a Mac mini that has no monitor?
Turn on Screen Sharing on the mini. Open System Settings, then General, then Sharing, click the Info button next to Screen Sharing and turn it on, and choose who may connect. If Remote Management is on, turn it off first: Apple says the two cannot be on at the same time.
From your MacBook you can then connect to the mini and see its whole screen in a window.
How do I stop a headless Mac mini from sleeping?
In System Settings, click Energy, and turn on Prevent automatic sleeping when the display is off. With no display attached, that is the setting that keeps the mini awake for you. Apple notes that preventing sleep can use more power.
Can I wake a sleeping Mac mini over the network?
Turn on Wake for network access in the same Energy settings. It lets the Mac wake briefly so that its shared services can be reached.
What happens after the Mac mini restarts?
After a power cut or an update, a Mac waits at the login window until someone logs in, and apps that run in your account, a window-sharing app among them, do not start until then. Automatic login skips that: System Settings, Users & Groups, then choose the account under Automatically log in as.
It is not always available. Apple lists three cases where the setting is dimmed: FileVault is turned on, the Mac is managed by an organisation that prohibits it, or the account logs in with an Apple Account password. Apple also advises against automatic login for an administrator account, since anyone who restarts the Mac then gets that account. Whether to trade disk encryption for automatic login is your call.
Does Wormhole work with a headless Mac mini?
A headless mini is the case Wormhole is built for, and it has not been tested on one yet. What is known: with no display attached, macOS can have no display at all to draw windows on, and then there is nothing to capture. When the mini reports no display and no windows, the window picker says so rather than showing an empty list.
The fix people use for every screen-sharing tool is an HDMI dummy plug, a small adapter that tells the Mac a display is connected. With one plugged in, the mini has a screen to draw on and its windows appear in the picker.
On the mini itself, turn on Open at login in Wormhole's Settings › General, so it is sharing again after a restart. A paired mini that has gone to sleep can be woken from the menu bar on your MacBook, on the same local network only; that has not been tested on a real sleeping Mac yet either. Both are on the known issues page, which is updated when they have been tried, and the FAQ answers the rest.