Well, there's definitely no built-in feature to merge profile data. The Sync service might mix some data from different profiles, but I haven't heard of exactly how to do that safely (i.e., merging instead of having one of them take over).

What data are you trying to combine?

1st off, thx a mill (jscher2000) 4 taking time out of schedule 2day 2 offer wut u could 2 try 2 help the matter. Now in answer 2 ur question, it my desire 2 merge everything. But as I now think about it, being that they're the same default profile, I think all I'd really need 2 keep r the bookmarkz & the search history I guess. And if that is in fact the case, would using the export (HTML) import method do the trick? The main thing is, I don't wanna loose the bookmarkz & history I already have saved in the backup profile.

For bookmarks, yes, Export to HTML from both profiles and then Import from HTML into both profiles (assuming you want both to match, or one-way only).

• Export Firefox bookmarks to an HTML file to back up or transfer bookmarks
• Import Bookmarks from an HTML file

Now, History (meaning URLs you visited) doesn't have any kind of export/import. You can archive history from one profile (places.sqlite database file) to a list using an external program such as:

http://www.nirsoft.net/utils/mozilla_history_view.html

(There might also be an add-on that could do it. I'm not aware of one.)

But I don't think there is a way to stuff the extracted data into a different Firefox profile using any tool I've seen.

If you had a few hundred dollars to hire a programmer familiar with SQLite databases, they might come up with a way using general database tools.

But in a different place you mentioned search history which in Firefox has a different meaning: it is combined with the history Firefox keeps for form field entries. There's no built-in way to export/import this data, and I don't know if there are third party/external/add-on tools for it.

Thx yet again (jscher2000) 4 the extra info, most helpful indeed. Give me ur input as 2 whether my line of thinking is correct or not. After some more thought on this matter, I arrived at the notion that if I used my profile from the last build I installed it should contain all the bookmarkz from that previous build & all the new bookmarkz that were added up til now yes? Bcuz if that is in fact the case, then all I need 2 do is, backup my current profile which would overwrite my current backup profile, then just install my new backup profile in the new build of firefox & then all new bookmarkz would be added 2 the bookmark folder, & then each time when I know that I'm gonna be installing a new copy of firefox I would just need 2 repeat the process yes? Or does it not work that way?

Firefox's bookmarks are stored as a set in a single file, not as atomic files in a folder like Windows favorites. There's no way to merge files to create a more inclusive set. The only way to add the different sets together is to export to HTML, then import to the other profile.