When you are in the Library window for Bookmarks, Browsing History, & Downloads History, the '''Views > Sort''' feature is temporary in nature; the "sort order" is for that display only and lasts only as long as the Library window is open. See this to do a permanent "sort" of your bookmarks which is done at the folder by folder level via the contextual menu item '''Sort By Name''' in the sidebar of the Library window. https://support.mozilla.org/en-US/kb/sort-bookmarks-quickly-find-ones-you-want IOW, if you want to"sort" the Bookmarks Toolbar folder, right-click on that folder. Similar for the "Bookmarks Menu" folder; and so on for each separate folder that you create in the Bookmarks Menu folder. Each of those "user created folders" would have their own "sort level"; the "sort" is at the level of each folder individually. Also, sorting can be done in the Bookmarks Sidebar in the main browser window; what you get with '''{ Ctrl + B }''' from the keyboard or via the '''Show sidebars''' toolbar button to the right of the 3-bar menu button. Just drag'n'drop to the order that you want, but don't go too fast - Firefox does need a bit of time to absorb changes that are done in quick succession. I keep an eye on the Windows Task Manager when I do massive rearrangement of my bookmarks and don't proceed any further until the CPU Usage meter in the System Tray drops.