Rumors that the iPhone 14 Pro could get an always-on display are looking more and more accurate thanks to hints within Apple's Xcode 14 development tool. 

As discovered by developers rhogelleim (opens in new tab) and Steve Moser (opens in new tab) (via MacRumors (opens in new tab)), the beta 4 for Xcode 14, Apple's development system for iOS, macOS and other software, contains some changes to the function for simulating an iPhone.

The crucial ones here concern the lock screen, with rhogelleim finding that adding images to a lock screen widget makes them appear in black and white:

Moser then built on this discovery with one of his own: that the simulated lock screen briefly changes how these widgets appear as it wakes up. 

You can see in the two images below, captured by Moser from the lock screen wake-up animation, that the cartoon whale icon appears first as just a silhouette in the always-on display (AOD) mode, while details like its eye and paler-colored belly are added later.  

This fits in with previous leaks around the so-called "Sleep" mode for the iOS 16 lock screen. These have suggested that it will be work by desaturating and dimming image elements to preserve power, while still showing their vague outline. This is also how the AOD feature works on the Apple Watch 7 and previous Apple Watches.

Apple has seemingly laid the groundwork for the AOD in iOS 16, which will launch alongside the iPhone 14 but is currently available in beta. The iOS 16 beta lets users add widgets and other customizable elements to the lock screen, and their simple monochrome designs certainly seem made with the intention that they'll be visible when the rest of the display is off.

An always-on display also needs the right kind of panel, namely one that's capable of displaying images at low refresh rates to avoid using too much power. Fortunately, other rumors for the iPhone 14 Pro say it will get an enhanced version of the adaptive ProMotion display that's already found on the iPhone 13 Pro and iPhone 13 Pro Max. This will apparently allow the new iPhone to scale between 1Hz and 120Hz, with the former number being exactly what you'd need for an efficient AOD.

We'll almost certainly not know for sure whether the iPhone 14 Pro will get an always-on display until September, the month when Apple tends to reveal its new smartphone each year. If you want to read up on other rumored upgrades, such as a 48MP main camera and new notch design, and find out how the basic model's chipset and display will differ, check out our iPhone 14 and iPhone 14 Pro hubs. 

And for more news from Cupertino, you might also be interested in our exclusive story on how Apple will kill the password forever.

Richard is a Tom's Guide staff writer based in London, covering news, reviews and how-tos for phones, gaming, audio and whatever else people need advice on. Following on from his MA in Magazine Journalism at the University of Sheffield, he's also written for WIRED U.K., The Register and Creative Bloq. When not at work, he's likely thinking about how to brew the perfect cup of specialty coffee.