YouTube lets you play 4K videos on low-resolution screens
The youtube app on Android allows you to play videos with a resolution of up to 4K. All you need is a phone with a 4K screen and a decent internet connection, and you’re good to go. However, it seems that Google has now opened unsupported video resolution options on some mobiles or tablets, allowing some users to play 4K videos on a device with a low resolution screen.
According to a couple of recent posts on the YouTube subreddit, the YouTube app on Android now allows you to play 4K videos even if you don’t have a compatible phone or tablet. As the following screenshot from Reddit user shows u / Liskowskyy, the app now displays all video resolution options up to 2160p60, regardless of screen resolution.
While some think this change is unintentional, one user in the comments on another thread Reddit user u/sssxun speculates that the change may not, in fact, be a bug. They claim that by allowing unsupported video resolution options on devices with lower resolution displays, videos will have higher fidelity than when played at a supported resolution. I tried this on a device with a 1080p screen, and videos seem to look much better when played at 2160p60.
As another commenter points out, the big improvement in video quality is due to the fact that higher resolution videos have a higher bitrate and thus less blocky compression artifacts on high motion displays. Playing higher resolution video on a lower resolution display also increases sharpness due to downscaling, making the video look better overall.
Unsupported video resolution options seem to be widely available in various versions of the YouTube app on Android. I checked a couple of phones and was able to find the extra resolution options on all of them, even though they run different versions of the app. This leads me to believe that it may have been enabled via a server side switch. We will update this post once we receive additional details about this change from YouTube.