Retina for WordPress

The main picture for this post shows a single iPad icon in pixel proportion to the original Mac OS desktop. As a pixel geek I love this image, it really sums up the leap in display resolutions made over the last twenty five years: A single icon using up more pixels than an entire OS desktop – wow.

We are now in an important phase in the evolution of screen resolution – the move to HIDPI or “Retina” displays in devices. From a user perspective this technology means that you can’t really see the individual pixels on a screen as they are just too-small-to-see, so a print like illusion is created. The first consumer HIDPI display was the iPhone 4, which quadrupled the number of pixels from the previous iPhone – from 320 x 480 to 640 x 960. Apple did this in an elegant way, by displaying 4 pixels instead of 1. So when displaying an image in a simple box, the retina display will be showing you 4 times the visual data. That device was followed by the iPad 3 with its dense 2048 x 1536 display, along with other tablets, and we now have laptops from Apple, the Google Pixel and a few other more ‘traditional’ devices with extra high resolutions.

This image shows normal resolution on the left & HIDPI on the right.

This image show a HIDPI simulation, but goes the other way round – the image on the left is a ‘normal’ image, the image on the right is one quarter the resolution (half the width & half the height)

In the mobile space things are leaping forward, with LG announcing a 5.5in (14cm) mobile display featuring 538 pixels per inch with a 2,560 by 1440 pixel display, quite incredible. Desktop displays are taking their time however (something to do with yields and substrates) and even HIDPI champions Apple don’t sell their own 4K HIDPI display to match their imminent MacPro (which can apparently run three of the beasts). But it will happen, and I think we can safely say that It will probably only be a few years (maybe five?) before the majority of screens and devices shipped by manufacturers will be HIDPI. It’s definitely time to think about your graphic asset production & UI development resolution strategy sooner rather than later (and if you are building up a body of content, making content that will still be being viewed in five years, then you need to implement one quickly).


Is this super-high resolution worth the fuss? HIDPI displays have an analogy with “real” HI-FI equipment; when first listening it sounds impressive, but the initial wave of novelty quickly fades, and it soon becomes your standard. Yes its crisp and clear but thats what you’re used to now. It’s not until you listen to music on a friends cheap stereo, or in the car, that you know you can’t go back to listening to mediocre equipment again – its all mushy and wrong. The Tipping point for HIDPI TV’s highly successful move from SD to HD shows people’s appetite for resolution, and what people now expect from their TV’s and mobiles, they will soon come to expect from the rest of the web (UHDTV however is going to be a much harder sell however mainly due to the content pipeline.) So when will creating all UI and graphics in HIDPI will be mandatory – when presenting normal resolution assets will just look old fashioned or worse be perceived as a sign of poor quality? Who now would really go and make a video for the web that wasn’t in HD?

It is hard to find metrics to make a good case for tipping date, so lets look at usage now and imagine what the landscape might look like in five years time. Currently around 15 per cent of web traffic is from tablets and mobile, around 50 per cent of which are HIDPI. This gives us perhaps 7.5 per cent, so lets add laptops and desktops and be generous by giving them 0.5 per cent of web traffic – creating a total of around eight per cent. Mobile and tablets are expected to represent 50 per cent of web traffic within five years, and its safe to say the vast majority of new displays produced will be HIDPI within this time frame.

There are a few other factors at play here though. Fibre broadband is growing fast (though not fast enough if you live in rural areas) so the bandwidth required to supply big images will soon be enough so as to not create an appreciable difference in page load speeds. Secondly early adopters of HIDPI devices tend to be the most influential, and probably contain the largest number of decision of decision makers. Lastly, codecs are getting better – MPEG4’s new H.265 codec will make 4k streaming a possibility by being twice as effective with bandwidth than its predecessor (H265 also support resolutions up to 8192 x 4320 which might be an indicator of where we might be in 20 years.)

Final Thoughts

Content is still king Even though its showing a slower adoption than our home screens, mobile is driving the move to HIDPI, and it won’t be more than a few years before working in high definition becomes the standard. But, as with everything to do with resolution, its not really about the pixels or the contrast ratios, its about content. In the same way that a bad TV programme in SD is still just a bad TV program even when shown in HD. So even though we should all be implementing HIDPI production strategies, our content strategies, what we are actually saying, will always be more important.