In order not to lose in the fight against their main competitors (Instagram and Snapchat), YouTube recognized the popularity of the vertical video.
The update also affected the usual 16: 9 format. Rollers will increase due to additional space on the screen.
Another good news is the absence of annoying black sidebands. Viewing videos taken for smartphones will now be much more enjoyable.
A special advantage was given to Android owners. If the desktop version of the night mode appeared in the last year, and iOS users on March 18th, a similar function for android introduced only now. You can test it in the settings section.368