I’m a big-screen fan. It’s the reason my primary Mac is still a 17-inch MacBook Pro, and why I have that hooked up to a 27-inch Apple Thunderbolt Display when I’m in my home office. When travelling, though, I have fewer pixels to play with. Sure, I could get a 15-inch Retina MacBook Pro, but I favor physical screen space over smaller screen elements.
There are existing apps out there, like Air Display, that let you use an iPad as a second monitor for a Mac, but they work via WiFi, which poses two problems. First, they often don’t work on WiFi hotspots, which you’re likely to be using when away from home. Second, even when they do work, there is an annoying amount of lag.
Which is where Duet comes in. Instead of using WiFi, it feeds the video signal from your Mac to iPad using a standard Lightning or 30-pin cable. Built by ex-Apple engineers, I figured it ought to be work well, so put it to the test …
Setup
Setup is very straightforward. Install the Duet iOS app on your iPad, then install the companion menu bar app on your Mac. You need to restart your Mac after installing the companion app, and then you’re done.
You can also run it on an iPhone. On an iPhone 6, it would be pointless, and I’m not convinced it would be that much more useful on an iPhone 6 Plus, but the option is there if you want it.
Connecting your iPad
To use your iPad as a monitor, simply connect it to your Mac using a standard Lightning or 30-pin cable (I use an Amazon Basics one, mostly because it’s black …) and launch the Duet app on your iPad. Within 2-3 seconds, the Mac will automatically detect the iPad and start using it as a second monitor.
I found the first time I connected it, it set the iPad screen to be the main one, with the dock and menu bar over on the iPad. This looked rather funky, giving a sense of what an iPad running OS X would look like, but isn’t the most useful setup.
Reversing that works the same as any other external monitor: just click the Arrangement tab and drag the menu bar back to the Mac display.
In subsequent launches, Duet remembered this setting, so it was a simple, one-off task.
You can also use it as a third monitor alongside a conventional one if desired.
In use
I have two Macs: a heavily-upgraded late-2011 MacBook Pro 17, and a 2013 MacBook Air 11. Duet says that the app works only with 2013 Macs and later (running OS X 10.9 or later), and this is pretty much correct–but not the whole story.
With my MacBook Air, performance is silky smooth. It’s indistinguishable from a conventional external monitor, even when playing video. I was incredibly impressed, and think you will be too. Judge for yourself:
[youtube=https://www.youtube.com/watch?v=GCBjUAV-AxQ]
Updated: My usage on my MacBook Pro 17 was carried out with pre-release software, in which cursor-lag was horrible. But with the latest version installed, responsiveness is–while still compromised–is still perfectly usable.
Touchscreen OS X
One really nice, uh, touch with Duet is that you can choose to control the apps on the iPad monitor using your Mac touchpad/mouse, or the touchscreen display on the iPad–switching back-and-forth between the two methods as you like.
It’s really quite fun to explore what OS X would be like on a touchscreen device. Obviously it’s not designed as a touchscreen OS, so a lot of the user interface elements are rather small for a finger, but for things like weblinks, it makes for a convenient additional means of control.
Issues
Generally when using an external monitor, it will be larger than your Mac display. In this case, it’s smaller, which means any large windows you drag across to the iPad will need resizing. It’s easier to make them small before you drag them and then resize them as desired once positioned on the iPad.
I found that if I let my Mac go to sleep, it wouldn’t always automatically reconnect to the iPad. Sometimes it did, sometimes it didn’t. When it didn’t, not even relaunching Duet on my iPad worked: I had to quit both iOS and Mac apps, disconnect the Lightning cable–then relaunch both apps and reconnect the cable. Conclusion: set your Mac not to sleep when using the app.
Things were fine at the iPad end: I could switch off the iPad when I didn’t need the second monitor, and it would reconnect to the Mac within a few seconds of switching it back on again. Same thing when disconnecting and reconnecting the cable. You can also use other iPad apps and just pick up where you left off when resuming Duet.
Conclusions
I love it. Used on a recent Mac, it’s as good as a conventional monitor (albeit a small one). Those who use chat apps for work will find it especially useful, enabling you to keep an eye on the chat while still retaining full use of your Mac screen for your actual work.
Even on older, theoretically incompatible Macs it is still useful for some applications. Granted, there is extreme pain involved in getting the app window positioned on the iPad in the first place, which could literally take several minutes when using my MacBook Pro 17, but once it’s there, it works just fine for things like Hipchat. It claims to work fine on older iPads.
At $14.99, it’s one of the more expensive iOS apps around, but given the boost it will give to your mobile productivity, I think it’s excellent value for money.
Duet requires a modern Mac running OSX 10.9+, and an iPad running iOS 7+. The Duet iOS app costs $14.99 from iTunes, while the companion Mac app is free.
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$300 for a 9.7″ retina monitor.
Or $0.00 if you already have one :-)
*14.99$
It’s only a solution if you already own an iPad.
In that case the joke would be on you for letting a salesman pitch you on a iPad only to use as a monitor for your MacBook.
Regarding resizing large windows.. combine Duet Display with the free app BetterTouchTool (http://www.bettertouchtool.net) and you can automatically resize the windows by dragging to different parts of the screen. If you’ve ever used Windows OS, it works just like that. For example, if I drag a windows completely to the right of my screen it automatically sizes it to the right half of my screen. To go full screen I drag the window to the top of my screen. This is just the surface of what BTT can do.
Personally, regardless of whether you use Duet Display or not.. you should get BTT.
Or, use Divvy app, which lets you bind key-combos to resize windows and snap them to pre-defined positions. I have a key-combo for full screen, which automatically snaps it to the largest possible size… and then lots of different positions around the screen. It has been incredibly valuable for me with 2x 27″ thunderbolts and my 15″ rMBP.
BTT is the best thing on a Mac, by far!!!
I tried Air Display for drawing on my Mac via the iPad, and was not impressed with the lag. Does Duet handle drawing in Photoshop well?
Hey Johnny,
We have illustrators using Duet successfully in their work. Duet will be much more responsive and reliable than Air Display since it’s a wired connection.
FYI, we don’t support pressure sensitivity yet though, if that’s a deal breaker for you.
Thanks for the reply. It is a deal breaker for now, but that “yet” gives me hope.
Certainly something we are interested in :)
Is it possible to use this as a 3rd monitor. i.e. MacBook, Thunderbolt Display and iPad?
I have it connected to a mid-2010 MB-Pro with no issues. Currently it is set-up as a third monitor. Again no issues and no lag.
Yes, it is.
I wonder if using USB 3.0 via a Thunderbolt dock would be smoother on a 17″ Macbook Pro.
Hmm, worth a try – I do have one
Giving this a try now and really liking it. At first I was shocked as the default mode was non-Retina, but a quick change in settings made it a Retina display. Works perfect with Better Snap Tool also.
Primary display on a Mac Mini? Mine’s headless, I usually screen share to a macbook.
I don’t think so, but Chrome Remote Desktop would seem to do the job: http://viptest.9to5mac.com/2015/01/12/google-release-chrome-remote-desktop-for-ios-to-access-your-computer-from-your-iphoneipad/
Here’s an idea… What about using a classic Mac case, use an iPad as monitor and an Mac mini inside so you can relive the classic Mac experience?
Yes, the iPad (or iPhone) can act as the only display for a Mac. To do so please install Duet’s Mac application with another display first.
Then disable your account login screen so that Duet will be able to load on OS X to display on your iPad during startup or a restart. (You can also change to list login and type your username and then press tab and type your password then enter, no screen would be displayed until you were logged in though)
Also make sure you keep “Launch at Login” enabled in Duet’s menu bar app preferences.
so I just bought the app and now I have my iPad 3 as a screen for my Mac mini which solves a problem that I had brilliantly. However, my Mac mini doesn’t have a camera on it, but my iPad does. Is there anyway that the software could received FaceTime video chats on my Mac Mini using my iPad camera?
I might add that you’d probably need a dummy dongle too (check this link: http://blog.macminicolo.net/post/33839671756/build-a-dummy-dongle-for-a-headless-mac-mini)
Who makes that stand and desk set shown in the top picture?
I’m not sure, that’s a stock photo from Duet.
Looks like the stuff sold by Evernote… not sure if they make them or just resell them on behalf of another company.
The iPad stand looks like a 12south Compass to me
Curious as well…
Found them here: https://www.evernote.com/market/feature/pfeiffer
anyone know where to get the gorgeous ipad/iphone-stands viewed in the main picture on top? The ones with the wooden panels… Thx
I was wondering the same thing! They really are gorgeous.
https://www.evernote.com/market/feature/pfeiffer
If I wasn’t using an Early 2008 MBP I’d jump on this but I’m afraid I’ll spend $15 and realize that it either doesn’t work or has so much lag it’s not worth using.
Another requirement, apparently, is having a lightning equipped iPad. I assume a 30 pin connector version isn’t going to cut it.
The front page of Duet’s web site claims it works with both lightning and 30 pin connectors.
30-pin is fine – sorry, I should have said that, will add a note.
On duets website they state all Macs 10.9 + so where do they say it only works with 2013 macs?
Edit: The software I had was a pre-release version. With the latest version, it’s still a little laggy on my MBP17 but perfectly usable, even for video.
Hey Ben,
Would you mind amending that quote “Duet says that the app works only with 2013 Macs and later (running OS X 10.9 or later), and this is pretty much correct–but not the whole story.”
Duet is compatible with All Macs running 10.9+, performance will improve based on the speed of your Mac’s processor. An older Macbook Pro, Mac Pro or Mac Mini with a faster processor than a post-2013 Mac will perform just as smoothly if not better.
Sorry to ask, but we’ve had some confused customers emailing us.
Cool, thx for info
This article really made me want a 17″ MacBook Pro again…
I’m officially a two computer guy. I have my 11″ MacBook Air, and I use that for most of my travel. My 15″ rMBP is usually plugged into a monitor, but I take it with me from time to time. Would love to do the same with a 17″ rMBP!!!
This will be perfect for doing homework on the go
This should really be a built-in feature of iOS and OS X – it’s the sort of seamless connectivity that Apple is known for!
(And when you plug your iPad in you should also automatically get audio/video/MIDI connectivity between both systems.)
Apple might build this in, but only if they could require the iPadAir 3 as the base hardware. Or whatever the next bit of hardware they want us to upgrade to..
Yes, it does seem like a missed opportunity by Apple.
I’m a 17″ MBP owner myself. I’m guessing the reason why you’re having the performance letdown is that the MBP 17 uses USB2 instead of USB3. But . . . . there are lightning to USB3 adapters. I have the Kanexx one. Will need to test this solution!
I wasn’t able to have it without a lag, after two updates as well. Ended up requesting a refund. I have other things to do than trying to wait for the developer to trying to make it work. It was not with minor issues, it was non-working at all.
For those of you, like me, that use Airplay Mirroring to Apple TV a lot, these 3rd display apps are not currently compatible. I use Duet but need to uninstall it when streaming from my Mac to my Apple TV.
I already work with a second screen. Will this app let me use my iPad as a third screen?
Yes
If you don’t need the touch capability of the iPad you’re better off with a cheap monitor. This is basically a novelty item for people who have a Mac and an iPad. I DO use air display but it’s for remote control of my system from a distance. Yes there’s lag but I deal with it because of the functionality it gives me. If Apple was really behind touch they would release a 27 inch touch screen companion monitor for the iMac line of computers.
Just bought the app. Disappointing that it cannot be used as a monitor while editing in Adobe Premiere. Once I move the Program window into my iPad it turns black.
I have similar experience with Photoshop. It crashes shortly after I open it while iPad is the only display.
Hi there, I have a 3 monitor Pc for gaming. I tried to use the Duet with my ipad as a 4th monitor to put a dash for my racing game. Before running the game all looks ok but as soon as I run the game the monitors (the 3 on the pc and the ipad) goes black and can not do anything.
Anyone can help me with this?
Thanks
I’ve been using something quite similar for a few years now called “Air Display”. Something absolutely required for our leverage of the application is using the iPad as a mobile extension of the workstation it is attached to. For us that means I take the iPad with me throughout the building and can leverage the horsepower of my workstation with the iPad, driving the workstation via my fingertips on the screen of the iPad. Air Display is available for the Mac but I have never tried using it at home. We happen to have three iPads at home not doing much. I should be using them as second and third displays. Thanks for the reminder!
I have been using my iPad pro as a portable second screen for my macbook and it works great. I especially like to to position the iPad in landscape mode to make reading documents easier (the UAG case is awesome btw). Sometimes starting duet display can take a few seconds, but when it connects there is very little lag. Is there a way to connect a second iPad pro to my laptop to have 3 screens on the go? I often work remotely and would love to maximize desktop space.
I work remotely and am often away from my home office setup. I really love using Duet with my iPad to add a little extra screen real estate to my 15″ rMBP. It works really smoothly.