What format do you want?

Native Backup Format

Firefox's native backup format is JSON using LZ4 compression. The files are stored in your active profile in a folder named bookmarkbackups and are updated approximately daily (less often if there are no changes). You could back up that folder. More info:

• Where is the folder: Profiles - Where Firefox stores your bookmarks, passwords and other user data
• How do you use the files: Restore bookmarks from backup or move them to another computer

Classic HTML Format

Most browsers can import an old HTML-format bookmark export file. I am not aware of a way to trigger an export from outside of Firefox. However, you can set Firefox to create an export at shutdown in a shared location on your computer (e.g., Documents folder), and then back that up.

To set that up:

(A) Open Windows Explorer to the folder where you want to send the exports. Keep this window open; later you'll select and copy the full path to the folder from the Windows Explorer address bar to paste into Firefox. For example:

C:\Users\username\Documents

(B) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(C) In the search box above the list, type or paste book and pause while the list is filtered

(D) Double-click the browser.bookmarks.autoExportHTML preference to switch the value from true to false

(E) Create a new preference for the export destination as follow:

(i) Select and copy the following preference name:

browser.bookmarks.file

(ii) Right-click a blank area of the page and choose New, then String. When the dialog appears asking for the name of the preference, paste browser.bookmarks.file and click OK

(iii) Now the dialog asks for a value. Leave that open and switch over the Windows Explorer. Select and copy the path from the address bar and switch back to Firefox and paste it. That may be similar to:

C:\Users\captainajb\Documents

Before clicking OK, if you want a custom file name, add that to the path. For example:

C:\Users\captainajb\Documents\auto-bookmarks.html

See also: how to set automatic backup for bookmarks

Jscher2000 - Thanks for the quick response. It was HTML. I will look at setting up the compromise solution.

Regards

These add-ons can be a great help by backing up and restoring Firefox

https://addons.mozilla.org/en-US/firefox/addon/febe/ FEBE (Firefox Environment Backup Extension)

FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.

https://addons.mozilla.org/en-US/firefox/addon/opie/ OPIE

Import/Export extension preferences

Its all too much :-) Thanks for further info