Backup and restore

Manual backup

1. Click the Library button 57 library icon on your toolbar. (If you don't see it there, click the menu button fx57menu then click Library.) Click Bookmarks and then click the Show All Bookmarks bar at the bottom.
2. In the Library window, click the I-B icon pre68 button and then select Backup….
3. In the Bookmarks backup filename window that opens, choose a location to save the file, which is named bookmarks-"date".json by default. The desktop is usually a good spot, but any place that is easy to remember will work.
4. Save the bookmarks json file. The Bookmarks backup filename window will close and then you can close the Library window.

Restoring from backups

1. Click the Library button 57 library icon on your toolbar. (If you don't see it there, click the menu button then click Library.) Click Bookmarks and then click the Show All Bookmarks bar at the bottom.
2. In the Library window, click the bookmark button and then select Restore.
3. Select the backup from which you want to restore:
4. The dated entries are automatic backups.
5. Choose File… lets you restore from a manual backup (see above).
6. After choosing a backup, your bookmarks from that file will be restored. Close the Library window.

Moving bookmarks to another computer

You can use Firefox Sync to move your bookmarks from one computer to another.

Firefox Sync is the best way to keep your bookmarks (and other profile data) synchronized between all of the computers you use. See How do I set up Sync on my computer? for more information and instructions on setting it up.

Using a bookmark backup file

You can also use a bookmark backup file from one computer and restore it on another computer. This is useful if you can't synchronize the two computers' bookmarks using Sync, for some reason.

The bookmark backup file can either be a manual backup (see above) or one of the automatic dated backups located inside the Firefox profile folder named bookmark backups folder. Place the bookmark backup file on your transfer media (for example a Flash drive) and copy it to the desktop (or any location) of the other computer. You can then restore the backup from the Firefox Library window, using the Choose File… option, as described in the Restoring from backups section above.

Thanks for the effort but the question relates to the icons, NOT the bookmarks. I have the json file backed up already. It is the ICONS that are missing, NOT the bookmarks. thanx

bit of progress:- A search for.ico files found the following location:-

C:\Users\t\AppData\Local\Mozilla\Firefox\Profiles\y5rr003a.default-release\jumpListCache

There were some icons here but only a few. Would they perhaps be stored in some other file format? tm

favicons.sqlite is the file where the Favicons for bookmarks are stored, so backup that file, too.

Tip: When you Export Bookmarks in HTML format the resulting bookmarks.html file does contain the Favicons. And that bookmarks.html format provides greater portability for bookmarks; just about every web browser that I have ever used allows Import and Export in the html format. BUT that is just for the bookmarks themselves, the Favicon data string, which is unique to Gecko and was added in 2004 long after bookmarks.html ended up becoming the universal bookmarks / favorites interchange format back in the Netscape / IE 4.0 days. That tip may or not be helpful for you with WebKit / Blink based web browsers - so YMMV.