Where are you trying to copy prefs.js to?

Copying the entire Profiles folder to a different installation of Firefox might not work because there is a file one level up named profiles.ini (at least on Windows that's it's name) which is needed for Firefox to know the individual profile folder names.

I see. Well, I have some 15 changes made on about:config, and I really would like to have a backup, so I dont have to go one by one when restoring firefox. And I understoodd the only way is having a copy of that file prefs.js, or the Profile folder.

Where? Anywhere, a folder, a usb... just together with the xpi (add-ons) and ini (adblock), the less work/more back-ups the better :)

You should be able to copy the full profile folder anywhere, no problem. It's best to fully exit Firefox first (use Quit from the menu) to ensure that files which are partially updated during the session are fully updated and closed.

The trick is, when it comes time to restore that folder to a new installation of Firefox, you'll need to edit the profiles.ini file to add the unique folder name so Firefox can find and use it.

That sounds a nice trick. and to do that, how do I have to change the profiles.ini, which by the way is outside Profiles folder. Im 0 programming, so could you tell me the lines and what I have to write or delete.

Dont mean to be nuisance, but would it be possible to do that trick copying prefs.js instead the folder? Am asking that because the folder has 40 mg and the file 8 kb, kind of easier/lighter

I'm not very familiar with profiles.ini. There probably are other volunteers who can tell you the best way to add the new (old) profile name to the file.

The prefs.js file is small, but you mentioned copying your extensions as well so I thought it might be most convenient to copy the entire folder. I think if you can afford the disk space, it's easiest to grab it all. That said, some of the information is duplicative, for example, the bookmarkbackups folder contains numerous dated backups (mine are over 1MB each). If you use any download sites that use IndexedDB (such as Mega), then you may have a very large indexedDB folder that you don't really need to carry around with you.

I have a backup of the extensions but yes, by copying the folder I can keep the preferences too, you are right. I actually will try to know how to change the profiles.ini for both cases, in case I want to restore without extensions.

So two last questions. Why the profiles.ini is outside instead inside the folder?

And, should I close this post and open another more specific, or I wait for other volunteers?

Thanks, you have been really quick.

I don't know why the profiles.ini file is in the Firefox folder instead of the Profiles folder.

The format of the file is described in this article: http://kb.mozillazine.org/Profiles.ini_file

Thank you for the info.

I finally got the way, no need to change profiles.ini

I was as close as far from getting it. I was replacing Profiles folder when firefox was open. But firefox must be closed, I must copy all the content from the extrange named folder inside Profiles, replacing it for the content of the new one after restoring.

1. Set firefox with all changes on about:config, extensions, tabs, etc that I like, and then close it, cmd+q 2. Copy all content from the extrange folder in Profiles (something like niwxnm2h.default-1384723124135) 3. Open firefox and restore it, closing it again when it restarts. 4. Now, being firefox closed, replace the content from the new extrange folder by the old / copied. 5. Done, just start firefox.

So now I have two copies, with changes on about:config and with about:config and extensions.

Link where I found it: https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles?esab=a&as=aaq

Cheers and thanks

I had a little mistake. I can remove step 3. If there was a problem I would have to restore, otherwise I can replace the estrange folder content as much as I want, only must be firefox closed.