If there's one thing that's better than the Retina display on your MacBook or iMac it's plugging in a second screen. That's all very well if you have a spare screen, or the cash for an additional display, but what if you don't? Can you use your iPad as a second monitor? The answer is, yes you can, although you may encounter problems with the latest version of macOS, as we will discuss below.

Using an iPad as a second monitor is an ideal solution for those who only have access to a small-screen laptop like Apple’s 12in MacBook or 11.3in MacBook Air, as it effectively doubles the size of the display, allowing users to be more productive.

Read on to find out how to use your iPad as a second screen for your Mac.

What you'll need

  • A Lightning to USB cable
  • An iPad
  • Software such as Duet Display, iDisplay and AirDisplay.
  • A Mac running macoS 10.13.3 or earlier - unfortunatly 10.13.4 broke some of the DisplayLink functionality that these apps rely on.

Problems

These apps use DisplayLink USB graphics technology, which can be used to connect computers and displays via USB, Ethernet, and WiFi. Unfortunately,  macOS 10.13.4 broke DisplayLink - and therfore apps like Duet Display and those mentioned above may not work if you have installed the update to High Sierra.

It may still be possible to use the iPad as a display - but only in clone mode. To do so, it's recommended that the DisplayLink 4.3 drivers are downloaded.

How to use your iPad as a second display

In this example we're using Duet Display, which was developed by a team of ex-Apple engineers. Duet Display allows you to use the tablet as a second display not just on your Mac, but a PC too.

Duet Display also provides limited touchscreen support, allowing you to tap and swipe your way around MacOS. It means you don’t have to spend your time moving your mouse between the two screens, which becomes especially laborious when using a trackpad and again, enables users to be more productive.

We'll show you how to set up Duet display to use your iPad Pro (or any other iPad or iPhone) as a second display for your Mac or PC.

Here’s an overview of how to use your iPad Pro as a second display using Duet Display, with more in-depth instructions below:

  1. On your iPad Pro, open the App Store and install Duet Display – at the time of writing, it costs £19.99. It’s a universal app, so it’ll also be available for use with your iPhone.
  2. On your Mac or PC, head over to the Duet Display website and download the Duet for Mac/Windows app.
  3. Install the Duet companion app for Mac or PC. This is an important step, as the companion app allows your iPad and Mac to ‘talk’ to each other. Follow the installation instructions, and restart your Mac to complete the installation.
  4. On your iPad Pro, open the Duet Display app and plug it into your Mac or PC using a Lightning cable (or 30-pin cable if you’re using an older iPad).
  5. The iPad Pro should be recognised by the Duet companion app, and your desktop should now extend across the two displays. You’re then ready to go! Quality settings can be tweaked via the Duet companion app on your Mac or PC to provide higher graphics, smoother refresh rates, etc. and to disconnect the display, simply close the app on your iPad.