A hidden upgrade has been discovered on the iPhone 15 and iPhone 15 Pro spec pages: the new USB-C port can now play 4K video with a single cable (via Macrumors).

Previously, Lightning to HDMI connections were possible on the iPhone, but required a specific dongle to manage them, and only a maximum 1080p resolution was available. Additionally, there was Apple's AirPlay wireless connection, which is often as easy to use as a cable connection. But for users who only want the security of a wired connection, Apple's switch to USB-C ports on the new iPhone is another piece of good news.

The spec sheet explains that you can now play content and mirror your iPhone screen at up to 4K HDR, 60Hz, as long as you have a cable that can transfer data at that speed and a display with a DisplayPort connector. Alternatively, you can use an Apple USB-C Digital AV Multiport adapter with an HDMI connection. This will still provide 4K resolution at 60Hz, but no HDR.

The iPhone 15 series has already introduced a number of upgrades, including a USB-C port, an upgraded camera, and Pro model-specific action buttons and titanium frames. But improving the iPhone's wired connectivity may portend exciting developments ahead, beyond just viewing stored video in 4K.

For one thing, Apple has introduced the gaming potential of the A17 Pro-powered iPhone 15 Pro, with AAA titles like "Resident Evil 4 Remake" and "Assassin's Creed Mirage" running on the device. While the idea of enjoying these games on a pocket-sized device is appealing, it would look even better if these games could be run from the iPhone on a larger display.

On the productivity front, Apple theoretically has what it takes to add Stage Manager from an iPad or Mac to the iPhone 15. Even the largest iPhone 15 Pro Max is still a bit small to try to use the computer's desktop-style interface, but a speedy USB-C connection to an appropriately sized screen could provide a low-intensity way to work when away from your main work device It could provide a convenient way to do so, though we may have to wait for iOS 17 or even iOS 18 updates first.

iPhone 15 pre-orders begin later today (September 15), with full retail availability beginning next week on September 22. Get to know them.