iPhone X supports YouTube HDR video
In contrast to other “competitors”, iPhone X now supports YouTube HDR video.
Now a new feature of YouTube has been introduced for iPhone X: support for HDR video playback. Hundreds of iPhone users say they were able to watch YouTube videos with extended contrast ranges. To access this new feature, users search for HDR videos, go to the three dot menu in the top right (this icon appears when you click anywhere on the video), then click on the Select -> Quality and finally select 1080p60 HDR mode.
By default, iPhone X is included in the list of high-end devices that support HDR video playback, such as the Samsung Galaxy S8, the Google Pixel, the LG V30, and the Sony Xperia XZ Premium. Unfortunately, this feature is not currently available on the latest iPad Pro models.