YouTube Playlist Sorter A-Z is a Firefox extension designed to enhance the organization of playlists on YouTube by sorting them alphabetically. This extension allows users to override the default sorting method, which is based on usage, providing a more intuitive way to manage playlists. It affects both the main sidebar and the modal that appears when selecting playlists for video additions.

However, due to a recent design update from YouTube, which has altered the way playlists are displayed, the extension's functionality has been partially diminished. Playlists are now accessible through a singular button that leads to a grid view, making the alphabetical sorting feature less impactful. Additionally, while the ability to save videos to playlists remains unaffected, users should note that the extension is considered deprecated and will not receive future updates.