iPhone 6B, for Big

Of all of the perennial requests for features in a new iPhone, a larger screen has long been at the top of the list. After five years of 3.5 inch displays, the iPhone 5 (finally) gained a taller, 4 inch screen, but it’s still significantly smaller than its competition from Motorola and Samsung. This being an “S” year, the iPhone wasn’t getting a new form factor; if the iPhone is, indeed, getting a larger display, it will happen in 2014.

So how big would that display be? Well, according to the Wall Street Journal, Apple has been testing phones with displays of between 4.8 and 6 inches diagonally. That’s a huge leap from the existing display size. I have no doubt that Apple is testing these internally, but I doubt a 6-inch iPhone is coming any time soon (or at all). It doesn’t make any sense right now, for reasons which will become clear in the next paragraph.

Earlier this year, Marco Arment speculated that a bigger iPhone would carry a 4.94-inch display. This is more realistic, because his justification was a reversal of the iPad Mini math: as the iPad Mini gained the pixel density of a non-retina iPhone, for a display of 7.9 inches, the iPhone would gain a 264 ppi retina iPad display, at 640 × 1136 pixels. It’s the production line, stupid. Sounds logical, right?

I’ve thought so, too, ever since Arment published that piece. However, I’ve recently been thinking about it more critically, and I now think that this is the less likely scenario. I believe that a future iPhone — possibly the 2014 flagship model — will carry a 4.5″ display at 326 pixels per inch, creating a display of 720 × 1280 pixels.

Before you fire up a new tweet to tell me about how fragmented this would make the iPhone ecosystem, read on: I think you might like my reasoning.

Increasing the physical size of the iPhone’s display without increasing its pixel count would basically just make a bigger iPhone with no real benefit. It would be a lower-density display, but it would also only support the same interfaces that designers are creating today; they would just be bigger. While it’s true that tap targets for buttons could shrink in pixel size while remaining the same physical size, that would only buy designers a few pixels in both directions, and developers would still have to take into account the size differences. Interfaces would remain similar, if not identical. So what’s the point in going to a physically larger screen, then?

On the other hand, an iPhone with a 720p display would provide significant benefits for designers to build new, interesting interfaces, which would directly impact users. A display which has 80 additional pixels horizontally and 144 vertically would open up a new world for iPhone interfaces, while the phone itself wouldn’t increase as much in physical size. Try printing this PDF for an actual-size comparison. I tried to keep everything in proportion for the two larger models, but it was eyeballed around the (measured) size of each display. The iPhone 5, however, should be entirely accurate, as its measurements are based on Apple’s schematic for accessory makers.

Are there complications? Yeah: 720 × 1280 is a perfect 9:16 ratio, while the 640 × 1136 display in the iPhone 5 is one pixel too wide (or 1.7 pixels too tall, but I like dealing with whole pixels). However will developers make apps work with displays of three different sizes? How will existing apps adjust before they’re updated?

For developers, the tech to compensate has existed since iOS 6. It’s called Auto Layout, and it works by drawing individual interface elements relative to those which surround them, according to various criteria. While it’s been in place for over a year, Apple has stepped up their recommendation of its usage in the iOS 7 documentation, because of iOS 7’s Dynamic Type feature. I believe that their rationale runs deeper, though.

Remember, too, that Apple now offers retina displays on each of their three major product lines: iPhones, iPads, and Macs. Designers have produced high-resolution artwork for all three platforms, and developers have rebuilt parts of their apps to accomodate. This year, they’ve brought a new UI paradigm to the table with iOS 7, and introduced 64-bit support on iPhones. Developers have readily adopted both. If there’s any single company that can convince developers and designers to rebuild existing applications for a new development target, Apple is it.

What about apps which haven’t been updated for a new display size? Well, I’m a bit stuck on this one. My guess is that they’d be scaled up to 720 × 1278, with one pixel of letterboxing on the top and bottom. This would be an embiggened and scaled version of the proportions of the iPhone 5 display.

What about that pesky supply chain issue? Simply, I don’t think it’s any more complicated to cut an iPhone 5 display to 4.5 inches than it is to cut a retina iPad display to 4.94 inches. The production line effects of either decision will likely be similar.

This is obviously just speculation. I have no idea if any of this is even remotely likely, and I have a grand total of no sources at Apple. But I doubt there’s a point in simply increasing the size of the iPhone’s display without increasing what can be shown in that space. I think the iPhone 5’s display change was a transitional one, used to get developers accustomed to Auto Layout and to consider what can be done with additional space. I think the next iPhone will be an even bigger leap.

I don’t think they’ll call it the 6B, though. That’s just stupid.