Unlike Mac OS X 10.14 that only supports 15 ESR (115.6.0) as the latest version, Sonoma will support the current release (121.0.1 and 122.0 is on the way) and you should use that version.

• https://support.mozilla.org/en-US/kb/firefox-users-macos-1012-1013-1014-moving-to-extended-support
• https://whattrainisitnow.com/calendar/

You can find the full installer of the current Firefox release (121.0.1) in all languages and all operating systems here:

• https://www.mozilla.org/en-US/firefox/all/#product-desktop-release
• https://www.mozilla.org/en-US/firefox/121.0.1/releasenotes/

See also:

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Thanks cor-el.

Is there any danger with this upgrade of the Firefox profiles being lost or damaged?

I was told in the Apple store that the transfer utility they use to move what I have on the old iMac to the new iMac, would transfer everything "as is" and then I would have to upgrade as applicable any 3rd party application I use and/or download drivers as needed, etc.

I assumed that this would mean that profiles, bookmarks, settings, etc. would be preserved. Does this sound right to you based on any similar experience ?

Have a nice weekend.

In my above reply I added links to articles about how to backup your profile folder or transfer files to another device in case Sonoma is on a new device.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Cor-el, thanks. As I explained above, I am buying a new iMac.

Does your answer mean that profiles (and maybe bookmarks) would not transfer when everything is copied over from one computer to another one?

Don't know how this tool works on Mac, the Firefox profile folder is in a hidden location.

Firefox uses two locations for the Firefox profile folder. One location for personal data like bookmarks and logins and another location for temporary files like the disk cache.

Primary location used for the main profile that keeps your personal data (Root Directory on about:profiles).

• ~/Library/Application Support/Firefox/Profiles/<profile>

Secondary location used for the disk cache and other temporary files (Local Directory on about:profiles).

• ~/Library/Caches/Firefox/Profiles/<profile>

In Mac OS X v10.7 and later, the "~/Library" folder in the Home directory is a hidden folder.

Thanks. I did locate with no problems the Profiles folder with the i74yg722.default file in it.

I assume you are saying that I should copy this file over to the new computer (maybe if not there) or just save it? I will have it accessible on the old computer.

Can one just upgrade the version I have now that will be transferred to the new computer (after everything is transferred over) or are you implying that a complete new install of Firefox (121.0.1 or 122.0) is needed?

You can copy certain files with Firefox closed from one profile folder to another/current profile folder to transfer your personal data. Note that best is to avoid restoring a full profile folder and only restore important files that are safe to restore/transfer.

• 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) and key4.db (encryption key/primary password) for logins saved in the Password Manager
• cert9.db for 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)

Cor-el, I truly appreciate the info that you shared, but I do not understand.

Is there a formally documented process for transferring Firefox with all of its needed assets to a new computer with a new OS?

If something HAS to be copied over, how would someone like me know which files have to be copied?

Why cannot one just copy over Profiles (if files have to be copied over individually)? What would happen if one did that? Can you explain why this is recommended "Note that best is to avoid restoring a full profile folder and only restore important files that are safe to restore/transfer"?

I am sure that I am not the first person using Firefox to buy a new computer with a new OS version.

If there is no documentation explaining how the Firefox transfer should be done (to avoid loss of bookmarks and any personalization, etc.), then could you or someone else who did this explain what exactly I should do, step by step?

The links you sent are helpful but based on them I still would not know what I need to do on the new iMac with the latest version of Sonoma on it, to continue to use Firefox on it without loss and problems. Now I am really confused and concerned.

My reply above your last reply shows what files as safe to restore, best is not to restore a full profile folder, but make other changes again. Most files re listed as well in this article.

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

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder.

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

Thanks, Cor-el. I am very sorry, but I didn't get answers to my questions. Due to this, I have this really bad feeling that something threatening is hiding behind this upgrade to the latest version of Firefox for Sonoma.

I am not a technical person. I am so tired of having to spend my days fighting technical issues that the vendors don't address, figuring out why this doesn't work anymore with that, vendors pointing to each other, etc.

Yes, you sent an "approximate" list of what would have to be copied over with the following note "You can copy '''certain files''' with Firefox closed from one profile folder to another/current profile folder to transfer your personal data. Note that best is to avoid restoring a full profile folder and only restore important files that are safe to restore/transfer.". I do not understand this in the context of what I have to do next, why I would have to copy over files, why a subset of files, which definite set of files, the danger of restoring a full profile folder (if that's required for whatever reason).

As I said, the transfer would happen to a new iMac with Sonoma. Apple will use their Migration Assistant to transfer everything from my current computer to the new one. I was told that Migration Assistant moves everything other than the OS including 3rd party apps, plug-ins, network and system settings, user profile info, etc. They will be copied over to the new iMac.

Can you please explain what this means for Firefox after the transfer, on the new computer, what are steps I would have to do on the new computer : can I just upgrade to the latest version as usually? Do I have to do anything else?

As I mentioned before, I am not assuming that I would be the first or only person doing this. I really would appreciate the help I am looking for. It should not be this time consuming and painful.

If everything else fails and I am faced with another fight to make Firefox work, maybe I just fall back on Safari as I cannot deal with this. It is very disappointing to see how hard is to get straight answers and help when needed.

Some files may contain profile or OS specific content and can possibly cause issues when copied from one OS to a newer OS, that is why I advised to only copy important data files and not the full profile folder.

You can copy the files I mentioned on the old device to a removable USB disk drive and use that device to transfer the files to the new computer.

Do you already have Firefox installed on the new device?

You can find the full installer of the current Firefox release (121.0.1) in all languages and all operating systems here:

• https://www.mozilla.org/en-US/firefox/all/#product-desktop-release
• https://www.mozilla.org/en-US/firefox/121.0.1/releasenotes/

See also:

• https://support.mozilla.org/en-US/kb/install-firefox-mac

I do appreciate your support on a Sunday.

I did not yet buy the new computer. I am in the planning phase, trying to figure out what major issues a new iMac with Sonoma I will have to deal with if I buy the computer soon, vs a few months down the road. I do not want to wait until the next version of the OS is out with its list of serious bugs and similar ones for the 3rd party apps I am using.

As I mentioned, everything I have on the old computer will be transferred (copied) to the new one by the Migration Assistant. This includes Firefox as a whole. There was no assumption of de-installing and re-installing Firefox. Does what you suggested mean that after I have the new iMac with Sonoma I have to:

1. De-install (or delete) the 115.6 version that will be on the new computer and re-install Firefox, delete (or overwrite) the files you listed from the Profile folder and then copy to it the files you listed from the old computer? Update Firefox to the Sonoma version.

OR

2. If possible, ask Apple staff doing the transfer to exclude Firefox and then install Firefox on the new computer and copy to it from the old computer the files you listed. I do not know if they can do this.

OR

3. Save the profile files you listed on a stick. De-install Firefox on the old computer before the transfer to the new computer. Install the Sonoma version of Firefox on the new computer after the transfer and replace the files you listed with the ones from the old computer.

Please let me know which one is the recommended approach. Would Firefox be cleanly de-installed (if that's needed) by dragging the Firefox icon in the Applications folder to the trash bin?

Obviously I want to preserve everything I configured, customized and saved for Firefox and have it on the new computer without creating or asking for all kinds of problems.

I do assume that if I follow best practices, hopefully Firefox will not have problems running with Sonoma.

Thanks.

Like I wrote above, your current Mac OS X 10.14 doesn't support current 116+ releases, so even if you would transfer all data to a new device, then you would still have to install the current release as you can't update from 115 ESR with distributionID: mozilla-mac-eol-esr115 to the release update channel.

• https://support.mozilla.org/en-US/kb/firefox-users-macos-1012-1013-1014-moving-to-extended-support

With the Firefox 121 or newer version you need to install anyway, I would recommend to create a new profile to prevent future issues with leftover settings. You can either use Sync to transfer a limited set of data or transfer selected files like I posted above. If the new device has an Apple M1 processor then even more installation settings are different.

Cor-el, thanks. I did understand that I do need the Firefox 121 version on the new computer. However, I have no idea what you now mean by "Sync to transfer a limited set of data" or to "create a new profile".... Sorry, but please do not assume that everyone is as knowledgeable as you are.

I also asked you : Would Firefox be cleanly de-installed (if that's needed) by dragging the Firefox icon in the Applications folder to the trash bin?

I know you want to help, but if I cannot get explicit answers to my questions, it doesn't help me...

See:

• https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer
• https://support.mozilla.org/en-US/kb/how-do-i-choose-what-types-information-sync-firefox

Thanks.

How about the question about de-installing Firefox: "Would Firefox be cleanly de-installed (if that's needed) by dragging the Firefox icon in the Applications folder to the trash bin?". Yes or NO?

If anyone moved to a new computer using Sonoma and is using Firefox on a Mac, I'd appreciate some more help. I do not understand how one copes over specified Profile parts from one Profile to the other. This shouldn't be like brain surgery. I cannot get clean, easy to follow and complete answers about the best and easiest way to make this transfer happen without loosing my settings. I did read all the pointed to links and again, I am NOT a technical person.