1. Check how many displays your Mac supports
Apple says the number of displays you can use at once depends on your Mac model and on each display's resolution and refresh rate. Look up your model's Tech Specs on Apple's website under "Display support". For example, Apple notes that a MacBook Air or MacBook Pro with the M3 chip can connect two external displays at the same time when its lid is closed.
2. Connect the monitors
- USB-C and Thunderbolt monitors can often connect with one cable that carries video, data and sometimes power.
- HDMI monitors connect to a Mac's HDMI port, or through a USB-C adapter or dock.
- Docks are convenient for one-cable setups. Make sure the dock supports the number and resolution of displays you want on your Mac.
Use the same ports for the same monitors every time. It helps the Mac recognize your setup and keep its arrangement.
3. Arrange and choose the main display
- Open Displays. Apple menu › System Settings › Displays.
- Click Arrange and drag the displays to match their physical positions.
- Drag the menu bar to the screen you want as main, or click that display and set Use as › Main display.
- Set each display's resolution by clicking its name. "Larger text" and "More space" trade sharpness for room.
4. Decide how Spaces work
In System Settings › Desktop & Dock, under Mission Control, Displays have separate Spaces controls whether each display has its own Spaces. With it on, the Dock is available on every display, and you can use Split View and Stage Manager on each one. With it off, the Dock appears only on the main display. Pick one and stick with it, because switching changes how windows behave.
5. Put your apps where they belong
| Goal | How |
|---|---|
| An app always opens on one display | Control-click it in the Dock › Options › Assign To › Desktop on Display |
| Two apps side by side | Tiling in macOS Sequoia and later: Fn Control Shift Left Arrow |
| Same picture on both screens | Set Use as to mirror, for presenting |
| Laptop lid closed | Connect power, an external keyboard and mouse or trackpad, then close the lid |
The catch: windows don't stay put
Once you've arranged everything, unplug the laptop and macOS gathers all the windows onto the built-in screen. Plug back in and many of them stay there. That's normal macOS behavior, and it's the reason layout apps exist.