Bonjour

What the screenshot shows is the "Recently Bookmarked" list that you see if you click the Library toolbar button. This list is a so called smart bookmarks folder that shows the result of a database query. This list is always sorted on the creation date (date added) and can't be sorted otherwise.

You can add the "Bookmarks Menu" button that shows the bookmarks in a drop-down list to the Navigation Toolbar via these steps:

• click the bookshelf icon on the Navigation Toolbar or alternatively use the Library menu in the "3-bar" Firefox menu button drop-down list
• click Bookmarks
• click "Bookmarking Tools", then click "Add Bookmarks Menu to Toolbar"

The Bookmark Menu button should appear on the Navigation Toolbar.

You can also drag the Bookmarks Menu button from the Customize palette to the Navigation Toolbar

See also "How do I add the Bookmarks Menu button to the toolbar?":

• https://support.mozilla.org/en-US/kb/bookmarks-firefox#firefox:win10:fx57

You can sort bookmarks in a folder by right-clicking this folder and choose "Sort by Name" (you can't right-click a bookmark to sort).

• https://support.mozilla.org/en-US/kb/sort-bookmarks-quickly-find-ones-you-want

First use keyboard shortcut Ctrl + Shift + B. Then highlight/select the folder you want to organize. At the top of the window, select 'Views' then 'Sort'. Then select the option you want, which as you've said is 'A > Z Sort Order'. Voila! You have to repeat this for each folder.

^: That doesn't work. The Views menu is for viewing purposes in the Library and is similar to clicking a specific column header to sort by that column. Once you close the Library then you lose this sorting and you also won't see it in the bookmarks sidebar. The only way to sort alphabetically without using an extension is by right-clicking a bookmarks folder.