I work with a MacBook Pro on my lap and don’t use an external monitor. But once in a while I
need just a little bit of extra room on my screen. Did you know your iPad, iPhone or iPod touch
can be an extra screen? Here’s how to make it happen.
How to use your iPad or iPhone as a second monitor
If you need just a little bit of extra screen space but don’t want to invest in a whole extra monitor
here’s how to press your iPad, iPhone or iPod touch into service. It’s actually very easy — with
the right, low cost software, and provided you’re using a WiFi network.
I’ve already set up my iPad, so in this Tip I’ll set up my iPhone.
This works for Windows users too.
Air Display apps make it work
To share out your Mac’s screen you need Air Display. The software comes in 2 parts: free server
software for Mac or Windows and a low-cost app for your iOS device (iPad, iPhone or iPod
The Air Display Settings screen.
Install the server software
Download the free Air Display server software and install it on your Mac. It installs as a System
Preference pane. To set up the software:
1. Go to System Preferences.
2. Look on the bottom line under other and click on Air Display. The Air Display
3. The first and most important thing is to turn the server on. To do that click beside On on
the left-hand side. You are now ready to connect to your Mac.
4. You may also wish to set the other Settings. When you’re ready, click the Settings tab
and choose how you want Air Display to behave.
Install the app on your iPad
1. Go to the App Store and find the Air Display app. Buy and install it on your device.
2. Find the app on your device’s screen and tap to open it.
Now you’re ready to connect the iPad or other device to the Mac.
Connect to an iOS device.
Connect the iPad to the Mac
1. Go back to Air Display in the Mac’s System Preferences and look on the Connect tab.
2. Click on the Device dropdown menu and choose the device you want to connect to. My
iPad’s named Acrux, while my iPhone’s called Spiral. The screenshot shows me
connecting to Spiral.
Once you select a device you’ll start to see the Mac’s screen on that device.
Mirror the screen.
Mirror the screen
If you’re not used to using an additional display with your Mac you may find that strange things
happen. This will be because the screen on an iOS device is a different size from the screen on
You may find that everything from your Mac’s screen is mirrored on your iPad. That means
both screens show exactly the same thing. This is very handy if you’re giving a presentation and
have a projector attached to display your screen to an audience.
Some less capable Macs only support mirroring.
If two differently sized screens both show the same thing then windows may change size and
Extend the screen
If you have 2 screens and a Mac that supports it you can use a second monitor to show
something different from what you see on the main screen. This is how I use my iPad, so I can
show a few windows related to my dictation software on my iPad while I mainly work on the
Arrange the screens.
Arrange the screens
Any time you have an additional monitor attached you can choose how to arrange the screens:
mirrored or side by side (or above and below). To set up additional displays:
1. Open System Preferences and click on Displays in the second row. The Displays pane
2. Click on the Arrangement tab. The tab shows an image of all the monitors attached to
3. Check or uncheck the Mirror Displays checkbox in the lower left part of the window.
Your screens may change in various ways, depending on your selection. You may find
windows move, fonts look bigger or smaller, and the desktop picture may alter on the
iOS device’s screen.
4. Each monitor is represented by a ‘window’ icon in the middle of the window. Drag the
icons around to arrange them as you like. Notice that if you click and hold on an icon a
solid red outline appears around both the icon and the screen it represents, helping you to
identify which is which.
5. Close System Preferences when things are arranged to your taste.
The window is partly on the main screen … … and partly on the iPhone screen.
Move windows to the second screen
I prefer to put my iPad to the top right of my Mac’s screen. To move a window to the iPad’s
screen I just drag the title bar of that window to the right of the Mac’s screen and then keep on
dragging. The window shows up on the iPad’s screen. Both screens now act as though they are a
single, wider, screen.
Turn Air Display Server off
When you’re finished using your iOS device as a second monitor go back to System Preferences
— Air Display and set the Server to Off.
In the Air Display settings check the box to Enable touch. That allows you to touch your iOS
device’s screen to make selections, check and uncheck checkboxes; select on-screen menus and
so on — just like using a mouse.
In the Air Display settings check the box to Show Air Display in menu bar. That adds an
icon to your menu bar that makes it easy to access the preferences, connect to devices and so on.
With the secondary monitor connected, call up the System Preferences Desktop &
Screensaver preferences pane. Each screen will show its own window where you can select
background patterns for each device.
MacBook Pro and iPad side by side on my makeshift standing desk.
The iPad’s a handy second screen for reference
When all I want to do is get a few palettes or information windows off my main screen so I can
easily refer to them this is a superb way to do it. It saves me having to buy and place a whole