iPhone and iPad Mac

Turn Your iOS Device Into an Extra Monitor With Duet

Mark O'Neill 15-05-2015

Everybody likes plenty of screens when working or browsing the Internet. It seems to be a geek’s rite of passage to brag about how many monitor screens they have (“you only have two?!”).


But now those of you who own an iPad can use a simple app to expand your collection of screens, turning your $500 tablet into a small, portable monitor. It’s called Duet.

How Does It Work?

Duet is a cross-platform app that enables you to add another screen to your laptop or desktop, simply by connecting an iPad to either a Windows or a Mac OS X computer. It was made by former Apple engineers, and it is so damn good that it blows away most other similar solutions, particularly those that relied on a network connection.

It’s not only multiple screen addicts who will find this useful. Screen real-estate is always at a premium, with open browsers and apps all competing for space. Wouldn’t it be nice to just stretch out a bit and enjoy some space?

The desktop software is free for the Mac and the PC but you have to pay $15.99 for the iOS companion app. Once you’ve bought that, head to Duet’s website and install the app on your Mac or PC, and on your iOS device. Then you’re ready to rock and roll.

All you need to connect your iPad as a second screen is the Lightning cable that came with your device — the same one you use to charge your iPad and iPhone. You can be forgiven for getting the cable mixed up with a Thunderbolt Why Apple's New Thunderbolt Port Is Awesome [Technology Explained] I/O ports aren’t a technology that folks spend a lot of time thinking about. Let’s face it – they’re not sexy. Still, ports are important. As the interface between your computer and everything else, your... Read More cable (I almost bought one) but no extra purchases are required. Use the cable to connect either your iPhone or iPad to either the PC or Mac OS X computer and start Duet on both. You will then see your main desktop mirrored on your iOS device.


You can even use your iPad’s touchscreen to move your mouse around, select text and right-click.

On Mac OS X:

Turn Your iOS Device Into an Extra Monitor With Duet duetmac

On a Windows PC:

Turn Your iOS Device Into an Extra Monitor With Duet duetpc

There’s just a couple of things you need to tweak. The first is to decide what resolution, frame rate and image quality you want to use. I suggest just leaving it at the defaults, but you’ll be forgiven for bumping it up to Retina quality. Duet suggests 60 frames per second (FPS) for the optimal experience, but you could drop it to 30 frames per second when using battery power.


Note: If you have an older Mac, or you’re using a machine with relatively low specifications, you might find that dropping the quality, resolution and frame rate takes the stress off your system and results in better performance.

Turn Your iOS Device Into an Extra Monitor With Duet duetsettings

You will also need to go into your Mac/Windows settings and decide where you want your new monitor to be – left, right, above or below your main screen. This will determine which direction you move the mouse in order to see the cursor arrow on the iOS screen.

On Windows, head to Control Panel > Display > Screen Resolution and drag the small display to wherever you want it:


Turn Your iOS Device Into an Extra Monitor With Duet duetscreens

On a Mac, you can head to System Preferences > Displays to do the same, and choose whether to mirror your screen or use it as an additional independent space:

Turn Your iOS Device Into an Extra Monitor With Duet arrangemonitors

After using Duet it in my daily workflow for some time now, I have to say that I am seriously impressed. It has already become an essential part of my daily productivity, and it’s nice to be able to put Netflix The Ultimate Netflix Guide: Everything You Ever Wanted to Know About Netflix This guide offers everything you need to know about using Netflix. Whether you're a new subscriber or an established fan of the best streaming service out there. Read More on the iPad and watch it while I focus on my work on the main screen.


There is absolutely no lag whatsoever. The movements are extremely smooth, which puts this app firmly in the “wow!” category.

What Is It Good For?

There are many practical uses you could assign to Duet. I previously mentioned watching Netflix 5 Ways To Enhance Your Netflix Account In Chrome The Netflix interface could use a little improvement, so I've found some Chrome extensions to make my Netflix account look prettier. And no, it doesn't involve a bit of lipstick and some rouge. Read More , and you could expand that to BBC iPlayer How To Watch TV On The Web With BBC iPlayer [Mainly UK Only] The Internet is becoming an increasingly important source for content of all media. There are legal and not-so-legal ways of listening to music, watching television and movies, playing games, and obtaining software. All via a... Read More , Hulu Hulu Plus vs. iTunes vs. Netflix vs. Amazon Instant Video: Which Is Best? Hulu. iTunes. Netflix. Amazon Instant Video. The lifeblood of online cinema and television. The new wave of home media. The providers of endless entertainment in which pants are not necessarily required. They are the contenders... Read More , HBO Go HBO NOW vs. HBO GO: What Are the Key Differences? If you're confused between HBO NOW and HBO GO, then this quick comparison will show you which one is more relevant to you. Read More , and any other streaming service. But with a dual display 3 Dual Monitor User Types That Make Good Use Of Their Setup Read More , you could also use Duet on your iOS device for :

CPU usage What Is A CPU and What Does It Do? Computing acronyms are confusing. What is a CPU anyway? And do I need a quad or dual-core processor? How about AMD, or Intel? We're here to help explain the difference! Read More is pretty low, although obviously this will all vary on what purpose you are using Duet for. Watching a streaming show for example will consume a much larger amount of CPU than say a static website.

Removing Duet Display

There seems to be no problem with removing Duet from your devices, if you ever decide to. However, this page claims that the Duet preference files for OS X are not all in the same place. You will need to use Finder to find everything related to Duet and delete them.

So What Are The Alternatives To Duet, The Wannabe Pretenders?

It would be a bit one-sided if we only presented Duet as a possibility to expand your screen real-estate. There are other options, which we will briefly cover below:

Maxivista ($50)

Turn Your iOS Device Into an Extra Monitor With Duet laptop as monitor

This gives you the opportunity to turn your laptop into an extension of your main computer. You can use the mouse of your main computer to drag windows and apps over to the laptop screen. However, compared to Duet, it is very pricey.

Air Display (around $15)

Turn Your iOS Device Into an Extra Monitor With Duet airdisplay 640x340

Air Display is probably the one that comes closest to nipping at Duet’s heels. It does the same as Duet – provides the ability to turn your other devices into other screens for your primary monitor. And like Duet, Air Display is free for the primary monitor, but you must pay for the device which is going to connect as the second screen.

The only thing which holds it back is the price. It is generally a little more expensive than Duet and price varies depending on what device you are using.

iDisplay ($10)

Turn Your iOS Device Into an Extra Monitor With Duet idisplay 640x322

This is another interesting alternative. The one big selling point of iDisplay is that it can allow several iOS devices to be connected to the main computer. You can also apparently move around with the second monitor (be it an iPad or whatever) and it requires no cables.

You will need to stay within the Wi-Fi to keep the connection, and as we’ve seen in the past the wireless solutions don’t provide a truly lag-free experience. The iPad version is $9.99 while the Android version is only $3.99. Bit of a weird price disparity there.

DisplayPad ($3)

Turn Your iOS Device Into an Extra Monitor With Duet displaypad

This is one for Mac OS X and iOS only (sorry Windows users). With DisplayPad, you can use touch functions to move things around. Tap your iPad once to click. A two finger tap to right click. And a two finger drag to scroll, just like on a laptop trackpad.

The big selling point of DisplayPad is the price – $3! However, you get what you pay for in life, so cheap isn’t necessarily better. Use the trial version periods to thoroughly test each one before opening your wallet and knocking the dust off.

Just Duet

In case you’re still wondering: Duet is great and well-worth the money. If you need an extra screen, you can’t go wrong. Granted, the smaller screen space on an iPad and an iPhone will feel extremely limiting to a lot of people. But if you only need it to watch your Twitter feed, or catch up on your Netflix queue, then it will be fine.

So how many screens do you have? Does quantity matter, or is it what you do with them that counts?

Related topics: Computer Monitor, iPad, iPad mini, Multiple Monitors.

Affiliate Disclosure: By buying the products we recommend, you help keep the site alive. Read more.

Whatsapp Pinterest

Leave a Reply

Your email address will not be published. Required fields are marked *

  1. Stiven
    October 9, 2016 at 8:34 pm

    Cool solution! Thanks

  2. Michael E Nolan
    May 28, 2015 at 6:16 am

    I have tried Duet with less than positive results so far... To be fair, I have tried to use it with two Windows 8.1 tablets, a Lenovo ThinkPad 2 and an H-P Stream 8 and an iPad Mini and I am now sure this not necessarily the target specs for this software, at this time, although you would not know this from the extreme lack of technical information on the Duet website and in the Apple App Store. I think Duet would benefit tremendously from publishing tight specifications on their website for hardware and software requirements. I have tried to work with Duet 'support' via email and although the publisher initially responded fairly quickly, I have not heard back after the second reply and never received any technical information. As of right now, I have had to reinstall Windows on the ThinkPad 2 as it appears Duet has installed a series of video and serial drivers that killed the Bluetooth config and was causing BSODs due to a 'igdkmd32.sys file' that appears to be part of their video driver install. I also uninstalled the Duet software off of the Stream 8 as I became concerned I may have similar issues with it, as well. I was looking forward to helping the publisher figure out what might be causing the failure to work with the iPad Mini and maybe even getting to work,but a this point I think I will just eat my losses (3-4 hours of R&D and the joy of reinstalling Win 8) and try to get my $15 back from the Apple Store. Caveat emptor, at least for now... on Win 8.1 tablets anyway. Sorry Rahul, you had your chances.