How to turn on Display Zoom in iOS Simulator for iPhone 6/6s or iPhone 6+/6s+

Question

Is it possible to turn on Display Zoom in the Xcode iOS Simulator for iPhone 6/6s or iPhone 6+/6s+ so that it is possible to test and optimize using that mode? On an actual device Display Zoom can be turned on in Settings > Display & Brightness however that option isn't listed in the iOS Simulator settings.

Answer 1

Display Zoom is not available as an option in the current Xcode 7 iOS simulator settings. However , it is actually possible to 'simulate' Display Zoom when running your app in the simulator.

Background

When building a typical project for iPhone, you generally specify a LaunchScreen.storyboard file and/or launch images in Images.xcassets for the iPhone 4/4s ( 2x ), iPhone 5/5s ( Retina 4 ), iPhone 6/6s ( Retina HD 4.7 ) and iPhone 6+/6s+ ( Retina HD 5.5 ) and set those details in the project's settings. (See image below.)

When Display Zoom is turned 'on' for a iPhone 6/6s device, the device runs the app as if it was running on an iPhone 5/5s sized screen, upscaling the app x1.172 to fit the iPhone 6/6s display. (Similarly, when Display Zoom is turned 'on' for a iPhone 6+/6+s device, the device runs the app as if it was running on an iPhone 6/6s sized screen, upscaling the app to fit the iPhone 6+/6+s display.)

Note - The following instructions require the removal of some launch screen image files. You might wish to attempt these changes on a duplicate of your Xcode project.

Simulating Display Zoom on the iOS Simulator

To simulate Display Zoom for example using the iPhone 6 simulator in Xcode:

1 - Remove the LaunchScreen.storyboard file.

2 - Remove both the Retina HD 4.7 and Retina HD 5.5 launch images in Images.xcassets . (Make sure to keep the Retina 4 launch image.)

3 - Remove the reference to the 'Launch Screen File' in your Xcode project's settings, under 'General', under 'App Icons and Launch Images'.

4 - Select the iPhone 6/6s simulator, and then 'Run' your app.

Running your app

When the simulator runs your app, it will detect that no launch images are present for iPhone 6/6s, so it will presume it must be an iPhone 5/5s app and launch it into the simulator upsampling a iPhone 5/5s sized screen to fit the iPhone 6/6s screen, just as the Display Zoom setting would display it!