How-To OS X

How To Screen Share to Your TV Using AirPlay in Mountain Lion

One of the great new features in OS X Mountain Lion is AirPlay wireless screen sharing. The feature is already available on iOS for iPads and iPhones, but now that it will be available on the Mac it opens up lots of new possibilities. For example, showing Keynote presentations on a large TV, Safari web browsing, videos or even games.

One important point to realise is that there is a very slight delay between what appears on your screen and what appears on the TV, because your Mac has to compress the picture and transmit wirelessly to the Apple TV box. This means that for real-time games such as car racing, it may not meet your expectations in terms of the frame rate and performance. For most applications though, AirPlay works fantastically well.

Given the low cost of the Apple TV box ($99 in the US), Apple has created an excellent presentation tool for business and educational establishments, using a product that’s largely viewed as a hobby!

AirPlay requires an Apple TV set-top box and simply mirrors exactly what’s on the screen of your Mac. It means that it’s extremely easy to view your computer’s screen on a HDTV without cables, and there’s an absolutely minimum of setup required to make it work.

AirPlay lets you see exactly what's on your Mac screen on a HDTV

What You’ll Need

Apple TV Set-top Box
The Apple TV Set-top Box is required for AirPlay

To use AirPlay with Mountain Lion, you’ll need the following equipment to begin:

  • An Apple TV set-top box
  • A Mac running OS X Mountain Lion
  • A HDTV that can show 720p resolution or higher
There have been some reports that older Macs also require a local wireless network connection (i.e. they need to connect to a wireless access point) but the latest models can create a wireless “ad-hoc” network with the Apple TV set top box. This means that for presentations on the road, all you need to take with you is an Apple TV and your Mac.

Mountain Lion Icon

How To Setup AirPlay

The first thing to do is to setup your Apple TV box, if you haven’t already done so. Full details can be found on the Apple website, otherwise follow these basic steps:

Setup and Configure Apple TV

You can stream your Mac’s screen wirelessly at up to 720p resolution, or the resolution of your screen if it’s lower than that. In future versions of the Apple TV, it should also be possible to stream higher resolution video (1080p). AirPlay also sends your Mac’s audio to the TV, so you can view high definition pictures and enjoy decent quality audio.

  1. Connect your Apple TV to a HDTV using either the HDMI cable or component cables
  2. Select the correct AV channel input on your TV that the Apple TV is connected to
  3. Connect the Apple TV to your wireless network – when prompted, use the Apple Remote to search for your network from the list and make sure you know the WiFi password
  4. Just follow the onscreen instructions to enter the necessary configuration information. You should also pair it with iTunes on your Mac and setup a 5-digit password, so that Apple TV can access your media library
Note: it’s important to run the very latest Apple TV firmware for it to work with Mountain Lion, which is available on Apple’s iOS development portal. When Mountain Lion is officially released, it will only be necessary to update your Apple TV in the normal way if you have an older system.

Setup AirPlay on Your Mac

To configure the proper display resolution on your Mac and to select the Apple TV device, go to System Preferences and choose Displays which is found in the Hardware section. This presents various choices to select the screen resolution, and also lets you choose which Apple TV box you will mirror the display to.

AirPlay Display Preferences
Select an Apple TV device in your Mac's Display preferences

Your Mac will automatically detect any Apple TV boxes when it’s on the same network, and display the various AirPlay options in your menu bar. Just click the icon and choose the correct Apple TV, and almost instantly whatever is displayed onscreen is mirrored on your HDTV set.

Several options are displayed in when you hit the AirPlay menu bar icon as follows:
  1. AirPlay mirroring off
  2. AirPlay mirroring set to one of the Apple TV boxes in range
  3. Match desktop size to AirPlay Device
  4. Match desktop size to This Mac

Normally it’s recommended to match the desktop size to the the Apple TV (option 3), but note this is currently limited to a 720p vertical resolution.

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About the author

Roland Banks

I've been passionate about Apple ever since I bought my first iPod followed by a white polycarbonate MacBook in 2007. I currently own a MacBook Pro Retina, an iPad Mini Retina, and an iPhone 6.


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  • Unfortunately not all devices are supported. I tried using it on my 2010 13″ MacbookAir and the Airlpay option does not show in the Display preferences.
    I read somewhere, the minimum requirement is an Core iX processor. My 2010 MBA has an Core2Duo.

  • I can confirm that Airplay is Not an option on a MacBook Pro – mid 2009 – with Core 2 Duo. ( Darn )

  • Guys, this feature will be available in OS X Mountain Lion which will be released this summer. Or maybe have you tried it with developer preview version of this OS?

  • Can we assume that audio will also be sent from the Mac to Apple TV when screen mirroring?