change default YouTube video quality to 720p or highest available below 720p. can be used for other video qualities by changing preferredQuality in the code below.
When you open a video in a new tab, either by middle-clicking a link or by clicking on the logo or title on an embedded video, the script doesn't work. Also, it doesn't work on channel trailers (the video that autoplays on the channel's home) even when opened in the same tab.
Videos in a new tab and channel trailer
When you open a video in a new tab, either by middle-clicking a link or by clicking on the logo or title on an embedded video, the script doesn't work. Also, it doesn't work on channel trailers (the video that autoplays on the channel's home) even when opened in the same tab.