Best answer: The answer is yes! Just like the regular Xbox One S, the Xbox One S All-Digital comes with 4K playback capabilities for streaming media.
Stream all the 4K things!
The Xbox One S All-Digital, like its disc-supporting cousin the Xbox One S, offers 4K playback for various media streaming apps to a compatible 4K display via HDMI. This includes apps like Prime Video, Netflix, YouTube, and Microsoft’s own Movies & TV digital purchasing service.
Naturally, in order to stream content in 4K, you need a 4K television, a 4K-capable HDMI cable (like the one included in the Xbox One S All-Digital box), and 4K content. Not all content on Amazon, Netflix, YouTube, and Microsoft Movies & TV is available in 4K resolution, so be sure to check the resolution of your media if you find that the final resolution output is blurrier than expected. Content streamed on Netflix and YouTube will automatically output to the highest resolution if your internet is fast enough, whereas 4K videos on Amazon or Microsoft need to purchased specifically, usually at a premium.
Save for the lack of a disc drive, the Xbox One S All-Digital is identical to the Xbox One S with all the same capabilities. While it can’t output games in 4K, the cable included in the box and the operating system both support UHD output for media. It also supports Dolby Atmos surround, making those 4K streamed movies all the more exciting.
An all-digital streaming device
While the Xbox One S All-Digital doesn’t support 4K gaming, it does support 4K playback for apps like YouTube, Netflix, Amazon Video, and Microsoft Movies & TV.