Apple's brilliant move makes the Duo unlike any other foldable phone when it comes to apps (UPDATE)

You might not believe it, but the iPhone Duo's internal display is 50% larger than the iPhone 18 Pro Max screen

According to Apple, when it comes to surface area, the iPhone Duo's inside display has about 50% more usable space than the screen on the iPhone 18 Pro Max. That's the case even though the former has a 7.6-inch screen and the latter's display measures 6.9 inches.To get to that 50% difference that Apple talks about, you have to include the estimated screen area, which is approximately 175 square centimeters and 117 square centimeters for the iPhone Duo's internal screen and the iPhone 18 Pro Max's screen, respectively.

Lastly, the wider 1:1.42 aspect ratio of the foldable Duo display compared to the taller 1:2.17 aspect ratio for the iPhone 18 Pro Max makes the Duo's display, when open, look more like a tablet.

The iPhone Duo's internal display gives app developers a giant new canvas to work on

With 50% more screen area to work with, the iPhone Duo display is giving app developers a huge canvas to work with as they build apps that will give Duo users new experiences for streaming entertainment, playing games, taking and sharing photographs, multitasking, and more.

Apple made sure that the aspect ratio for both the internal and external Duo displays was exactly the same. This allows users to move apps between the two displays allowing the app to look proportionally the same whether moving it from the smaller external screen to the larger internal screen or vice versa.

Apple makes a huge decision that arguably makes the iPhone Duo the best foldable ever made

What makes this a huge win for Apple (and a brilliant bit of tech design) is that the Duo's main competition, like the Galaxy Z Fold 8, the Motorola Razr Fold, and the Pixel 11 Pro Fold, do not share the same aspect ratio between the internal and external displays. That gives the Duo a huge advantage.

For example, on the Pixel 11 Pro Fold, an app is switching from an aspect ratio of 19.5:9 on the tall and thin cover display, to a 1:1 ratio on the wider and squarer internal screen. This causes some negatives to occur:

• UI elements move or break, and some apps are forced to restart when transitioning screens.
• Black bars appear on the sides of an app that doesn't know how to fill a square.

But since both the external and internal screens on the Duo share the same aspect ratio, an app's layout simply scales up or down when you move from the outside screen to the inside screen, or vice versa.
Starting on the Duo's release date of October 23, more apps designed for the foldable will be available from the App Store. Throughout the remainder of the year, more apps for the first foldable will be released by the tech giant.

How to find apps for the iPhone Duo from the App Store

Inside the iOS app storefront, you'll be able to quickly find apps for the foldable thanks to their "Made for iPhone Duo" badge on product pages. And these apps will take advantage of the foldable's unique features.

For example, imagine going through your Clips feed on the Netflix app, viewing these streaming video snippets vertically, then opening the Duo to view clips on the internal display on which it is shown to you in a horizontal format.


With the iPhone Duo, users will be able to put the device on a table partially folded. The upright half of the display will show the live action as it occurs and the other half of the screen resting on the table will show the box score and other stats that are updated instantly.

Plenty of third-party apps will be taking advantage of the larger internal screen. On rideshare app Lyft, riders will have more room to look at different ride options while viewing the route they will take on a larger map.

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