Firefox comes in two or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox folder, the user profiles would not be affected.

You can backup persdict.dat in the Firefox profile folder.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

You can backup files like these with Firefox closed to save specific data.

• bookmarks and history: places.sqlite
• bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
• cookies.sqlite for the Cookies
• formhistory.sqlite for saved autocomplete Form Data
• logins.json (passwords) and key4.db (58+) or key3.db (57 and older) (decryption key) for Passwords saved in the Password Manager
  if you only have key3.db then make sure to remove an existing key4.db
• cert9.db (58+) or cert8.db (57 and older) for (intermediate) certificates stored in the Certificate Manager
  if you only have cert8.db then make sure to remove an existing cert9.db
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
• sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)

See also:

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

I appreciate your help, but I checked the file, it's extremely small. I'd like in future editions the ability to save this to the cloud. Thanks for your help though.

Hi, Firefox Volunteer Support can not help you with your wish.

Please go to 3Bar Menu --> Help --> Submit Feedback.

Make your request there for what you wish for and it will be reviewed by a team.

Considering Firefox does not have cloud storage I doubt this will happen.

The size of the file is small due to you making or added very few words. If you want to save things like that get a online email account like yahoo and email it to yourself for storage.

Also bookmarks.

Always do below or loose sooner or later :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Bug 409969 - Sync custom dictionaries Bug 1269548 - [meta] Sync more things

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)