. https://www.lightreading.com/video/4k-8k-video/blog-comcast-x1-supports-youtube-4k-streams-/d/d-id/748332
blog article
Starting today, Xfinity X1 customers can watch YouTube’s industry-leading catalog of online 4K content on the biggest screen in their home. More than 400 hours of video are uploaded to YouTube every minute across different formats, and since the launch of YouTube on X1 last year, “YouTube” is among the most popular voice commands.YouTube is also home to the most wide-ranging library of online 4K content – from scenic nature videos to movie and video game trailers and gaming content. Its availability over the Internet on X1 marks a significant step in our commitment to expand the 4K programming choices available for our customers.Customers with an X1 voice remote can say “4K videos on YouTube” to launch the library of 4K content available in the YouTube app or they can navigate to the YouTube app via the apps menu and enter a search for 4K videos. YouTube 4K content is denoted by a 4K icon below the video title. READ MORE