Firefox 72 is quite old, but at least should have converted the logins to using key4.db for the key file.

Note that best is to use the current release to get the latest security fixes.

• https://www.mozilla.org/security/known-vulnerabilities/firefox.html

You simply install the Firefox version you want to use and drag the Firefox application out of the DMG folder to the Applications folder on your hard drive.

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

If you want to experiment with different Firefox versions then you need to make sure to create a dedicates profile for each version (Firefox won't allow to downgrade a profile).

Installing multiple versions on Mac OS X is basically dragging the Firefox application out of the DMG file to the desktop and rename the folder. You can drag the renamed Firefox application folder to the Applications folder like you would normally install Firefox. You can possibly eject the DMG file and and trash the installer.

You need to use the terminal to create a new profile for that version. Firefox also comes with the about:profiles page that has a button to create a new profile. Make sure that no profile is selected as Default=1 to make the Profile Manager show when you start Firefox. You can check that in the profiles.ini file.

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

Hi Cor-el,

Yeah I know, I didn't mean to leave it so long before updating!

Does the new version not conflict with the current version in the folder then?

I'm not looking to have multiple versions of Firefox at once, so I don't need to create a new profile, right? It sounds like the process of renaming the new version means I'd have two version running at once - is there a way to avoid that?

Sorry for all the questions, I just don't want to do something wrong. And thank you for your quick response.

Best is always to let Firefox update to the current release via "Firefox -> About Firefox" to ensure proper profile migration. If that doesn't work then you can install the current release. What such a large jump in versions best is to keep a backup of all important files in case files get corrupted.

• https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

I understand that keeping Firefox updated is the best thing to do, and I will try to do that in the future, but at the moment that is not ideal for me. If what doesn't work? I apologise if I'm misunderstanding, but your first two sentences both suggest the same thing. Good point with backing up the bookmarks, shall do, thank you. But I'm not any closer to understanding how to update my current version of Firefox to a specific version without having multiple copies or profiles.

hello n -

sounds like objective is to install multiple versions of FF without creating conflicts between them.

this can be done by installing the unique version of the software into a custom folder. Otherwise the automated installation will select and use the pre-designated default folder.

Thus if you choose FF78 then custom install it to a folder called something like \FF78

Hello dbben,

It seems I'm not making myself very clear, for which I'm sorry. The objective is to have one version of Firefox, which would preferably be an update to the version I have currently but without being the latest version, and without losing my current profile or settings. Unless you mean that I have to have multiple versions in the process before removing the old version? If so, how would I go about the process?

So your objective is do a control upgrade to a specific version, instead of upgrading to the current version that is being disseminated by Mozilla.

Again, you will need a side by side installation of two browsers.

Then via the operating system file/folder management system copy your FF user data files over to the folder for the newly installed version.

Afterwards if the newly installed version is 100% functional and up-to-date with your user data, then you can delete the older FF directory, or keep it handy in case of emergency.

Note: Sometimes files are not copy-able between versions. But it doesnt hurt to try, especially if the file names are the same. There is a workaround. When files are incompatible the data in them can be export from one program and then imported into the other program. So in FF, export the FF logins, bookmarks, pws, etc.., aka FF user data, from the older installation and then import that data into the new installation.

That is correct.

I guess I should have figured there wouldn't be a simpler way given that Firefox would rather people keep their browser up to date. When I copy the user data files over to the new install, do I need to delete the newly created user files first, or would a box pop up with the option to replace them?

Wouldn't trying to copy files that aren't copy-able mess up the process? And I'm not sure I understand the difference between copying the files and exporting them, sorry.

Thank you for your help so far.

Please feel to experiment. I know you are trying to learn something new here.

If something does not go well with the new install then remove it and start over again. Then use alternative methodologies to accomplish the objective.

Keep me posted of your pitfalls and I / we can help you out.  :-)

Indeed I am, but I'm not sure I feel comfortable experimenting at this stage - I don't have all the information I need to not risk messing it up and losing data. Does anyone here have successful experience with custom updates or know the answers to the questions in my previous reply?

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.

• 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
  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)