The Great Smartphone Screen Size Debate

By Wesley Fenlon

Did Apple decide 3.5 inches was the "perfect" screen size way back in 2006, or is it just waiting for the right moment to adopt a larger display?

In early 2007, Apple ushered in the modern smartphone market with the launch of the iPhone. It had a 3.5-inch screen. In late 2011, Apple unveiled its fifth generation iPhone, which will be one of the fastest mobile devices on the market for months to come. It still has a 3.5-inch screen. Despite market trends towards screens that measure 4 inches or more on a diagonal, Apple's only significant change to the display came with the 2010 resolution doubling to 960x640 pixels.

Is the iPhone's screen really big enough? After last week's announcement, the tech community has split along two lines of reasoning. One: 3.5 inches is perfect because you can reach the whole screen while holding the phone with one hand. Two: larger screens are more appropriate for multi-purpose devices. While the 3.5-inch form factor does have its advantages, Apple's getting a bizarre amount of positive credit for sticking to a four year-old design decision.

Let's examine the arguments for and against the 3.5-inch display, and whether it Apple is really sticking to it because it's really the optimal size for a smartphone screen.

Credit: Dustin Curtis

The iPhone screen's defenders have been citing a recent blog comparing the phone's 3.5-inch display to the 4.27-inch screen on the Galaxy S II. Author Dustin Curtis makes a salient observation: it's easier to reach the corners of the iPhone in a one-handed grip than it is with a larger Android phone. In some use cases, this will be a problem for Android users. But it's also a simple argument that doesn't really take into account how we use our phones or where we put our hands.

Holding the 4.3-inch EVO 4G in the left hand, we can easily reach all but the top right corner of the display with a thumb. The Android notification tray is easily accessible, the menu buttons and app tray are perfectly positioned, and the keyboard works just fine for one thumb typing. There's also a very big gap between 3.5 inches and 4.3 inches--room for Apple to grow into without going "too big," if that's a legitimate concern.

Writer Charlie Stross makes an important observation about how we use our phones, pointing out that the one-handed grip isn't the only use scenario. In general, we use our smartphones for text-based communication--Stross appropriately calls them "text terminals"--more often than we do for phone calls. Typing and web browsing are both more efficient with two-handed grips, and larger displays provide more screen space for soft keyboards.

Stross' second point revolves around the first world's demographic transition towards an older population. As the population skews older, eyesight becomes more of a concern, and larger screens are naturally a bit easier to see for adults who run up against long-sightedness early. This is obviously a larger problem than the iPhone's screen, and the relationship between our eyeballs and LCD screens is only going to get more complicated.

Here's where Apple seems to be getting more credit than they deserve: writers assume Apple hasn't made the screen bigger because they think it's the perfect size already. John Gruber writes:

Now, maybe you would prefer a 4-inch screen. Or maybe a 4.5-inch screen. And maybe someone else would prefer a slightly smaller 3.25-inch screen. That’s not how Apple rolls, especially with iOS devices. There is no doubt that some people would prefer a bigger screen. But nor is there any doubt that many other people would not. I wouldn’t. I like to see things get smaller, not bigger. Bigger is not necessarily better. Apple decided on the optimal size for an iPhone display back in 2006. If they thought 4-inches was better, overall, as the one true size for the iPhone display, then the original iPhone would have had a 4-inch display. It’s not like 4-inch screens are harder to make, or use some sort of new technology. If anything they’re surely easier to make, as the pixels are less dense.

In 2007, Apple put out a phone with a 480x320 resolution screen because that was what was available at the time, not because it was the perfect resolution. No one else was making full touch phones without keyboards at the time. In 2010 they doubled that resolution while retaining the same dimensions to create an incredibly sharp picture--and to make iOS development easy, since the platform wasn't based around flexible resolutions.

In 2011 Apple stuck with that 3.5-inch display, but not necessarily because it's the perfect size. It makes more sense that they stuck with 3.5-inches because they clearly wanted the iPhone 4S to be consistent with last year's phone. The same body design works well because, externally, the phones are all but identical. Does Apple's decision in 2011 mean the iPhone's screen will never get bigger? No way.

It may take another few years and another resolution jump, or maybe just a software change to support a wider range of resolutions. But as we start to do more with our phones--and use two hands to be more productive with our "text terminals"--a trend towards larger screens will be completely natural. Our prediction is that Apple will only stick with its 2006 design as long as it's viable for the market.