No, each OS has its own conventions and Mac is quite different than Windows. It's a different OS and a different file system and the profile folder will be in another, hidden, location. The files in the profile folder will be the same, but different content makes files like prefs.js not being compatible. SQLite database like places.sqlite (bookmarks and history) and some JSON files like logins.json/key4.db for the logins and sessionstore.jsonlz4 for session data (open tabs) are Okay as well. You can use the OS selector of a SUMO knowledge base article to see some of the differences. *https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile ---- You can copy certain files with Firefox closed to the current profile folder to transfer or recover personal data. Note that best is to avoid copying a full profile folder. <hr> *bookmarks and history: places.sqlite *favicons: favicons.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 (encrypted logins;32+) and key4.db (decryption key;58+) for Passwords saved in the Password Manager<br>key3.db support ended in 73+; to use key3.db in 58-72, make sure to remove key4.db *cert9.db (58+) for (intermediate) certificates stored in the Certificate Manager *persdict.dat for words added to the spell 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)