For some reason, YouTube doesn't let you sort playlists by criteria like views and lengths of videos.
So, I made pl-sort. It allows you to enter a playlist link or id and sort it by views, duration of videos, like/dislike counts, title (alphabetically), date of publication, and of course, the default order.
It also shows you the total duration of the playlist.
For fun, I tried to make the interface as close to YouTube's official design.
If you need this frequently, you can install the extension for your browser. This adds an option to open a playlist directly in pl-sort by adding a "Open in pl-sort" option to context menu when YouTube playlist links are right-clicked.
To contribute, submit your issues and feedback on GitHub.