Is that a bookmarks.html file or a JSON bookmarks backup file?

Places Maintenance {web link} Allows to run Maintenance tasks on the database that drives Places, the bookmarks and history module behind Firefox.

Open the Add-ons Manager. Locate the add-on and press the Options button. Then follow the directions.

It's a standard file bookmarks file

Is this an automatically created compressed .jsonlz4?

You can make Firefox create an automatic HTML backup (bookmarks.html) when Firefox is closed by setting browser.bookmarks.autoExportHTML to true on the about:config page.

• http://kb.mozillazine.org/browser.bookmarks.autoExportHTML

This HTML backup is created by default in the profile folder as bookmarks.html every time you close Firefox, but you can set the path and file name via the browser.bookmarks.file pref on the about:config page.

• http://kb.mozillazine.org/browser.bookmarks.file

The browser.bookmarks.file pref doesn't exist by default and you need to create a new String pref with the name browser.bookmarks.file and set the value to the full path of the backup bookmarks.html file including the file name.

Note: an HTML backup doesn't preserve tags and annotations, so you lose those if you need to import the HTML backup.

• http://kb.mozillazine.org/Export_bookmarks

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

froggy said

It's a standard file bookmarks file

Which one? What is the file suffix?

It's still not working:-)

Can you give us the details we asked for about what kind of bookmarks backup this is about?

I assume that you have created an HTML backup if you are able to inspect the file in a Firefox tab.

Are there still an automatic compressed .jsonlz4 backup created after you have modified a bookmark?

• Bookmarks > Show All Bookmarks > Import & Backup > Restore

See also:

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