Browser data import from opera
For import data from another browser offers only MS IE, how to import from Opera?
Wšě wotmołwy (2)
That is not really part of firefox help here. But if you did do a search you find there were a couple threads on this already.
Wot WestEnd
https://support.mozilla.org/en-US/kb/import-bookmarks-data-another-browser
Only Internet Explorer, Edge, and Chrome are available for Firefox to "Import bookmarks (and maybe other data) from another browser"
In Opera, look for the option to Export bookmarks in html format which might be in the File menu. It was located there in the old Presto version of Opera.
Then import that bookmarks.html file into Firefox. https://support.mozilla.org/en-US/kb/import-bookmarks-html-file
Importing "other data" just isn't possible. Limits by the "other browsers" not being setup to "export" and with Firefox - as there is no common file storage system for interchange as there is with bookmarks data.