Firefox should be able to import a bookmarks.json backup. Firefox automatically creates a compressed .jsonlz4 backup in the bookmarkbackups folder. You can backup the bookmarks in two ways via "Import and Backup" in the Library. One is as an uncompressed .json backup, make sure to give the file .json file extension.

• https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

Another way is to create an HTML backup.

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/import-bookmarks-html-file

Note that restoring a JSON back replace all bookmarks with the bookmarks in this backup, you lose newer bookmarks that aren't in the backup. Importing an HTML backup merges the imported with the current bookmarks.

"Another way is to create an HTML backup.

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/import-bookmarks-html-file"

There was no option to create an HTML file during the "create backup file" process. Json was the only option.

What steps you mean with "create backup file" process, can you give more detail? Are you doing this in the Bookmarks Manager (Library; Ctrl+Shift+O)?

Thanks, Cor-el. Inadvertently really, your reply and question made me look twice at what I'd been doing. As it happens, I was trying to "back up" my bookmarks, whereas what I was actually intending to do was "export" them as an html file. And this IS an option in the Bookmarks Manager (Library; Ctrl+Shift+O)... as long as I don't click on "backup" in the drop down menu. Clicking "backup" only offers the json format.

So the answer to my original question is that I was inadvertently doing the wrong thing! In my mind I was trying to "backup" my bookmarks to my laptop HDD as an html file. I guess I'd done this before in order to transfer the bookmarks to another browser, but got the backup vs export confused.