Firefox on Mac: Slow, slow, slow

"30 minutes to startup means there is something wrong and my first guess would be an extension that does not behave.
I would try to disable all extensions and see if it is still slow.

The easiest way to do this is to start
Firefox in safe mode.
Here is quote from the mozilla support site how you can do this on your Mac:


Close down Firefox completely:
On the menu bar, click the Firefox menu, and select the Quit Firefox menu item.
Hold down the Option key, as you start Firefox
Firefox should start up with a Firefox Safe Mode dialog.


If that helps you can start in normal mode and disable your extensions one after another
until you find the culprit.

If it does not help I would try to start Firefox with a fresh profile:

Close Firefox and backup your profile
Start Firefox (it will create a fresh profile)
Restart Firefox to see if the problem still exists
Close Firefox and restore your profile

Backup and restore of the profile is really simple, there is a detailed explanation at
mozilla's support site."

"I had exactly the same problem with Firefox on a MacBook. I had no extensions for Firefox, no specific extra downloads, so that I could not say what was causing the problem by doing a safe mode start up.

I backed up my profile, and removed two files from my profile folder: the places.sqlite, which was like 8Mb then 3Mb after the vacuum command (it did not help by the way), and the urlclassifier.sqlite, which was like 5Mb.

And now, everything works like before. And I did not lose any bookmarks or toolbar bookmarks.

I don't know how Firefox uses these files but perhaps they should be cleaned off from the profile folder once every few months to keep Firefox in good shape."

You could try using Firefox's Refresh Feature which performs a bunch of cleanup operations. It can be accessed via the link or may be accessed from the about:support (this needs to be typed or copy/pasted into a new tab/window) page which also handily lists a range of details such as installed extensions and modified about:config options which can also cause issues. If you want to keep a record of your config you can just save the content of about:support page as a web page before you perform the refresh. Also beware that the 'refresh' wipes your client certificate store (it is mentioned on their webpage) so make a copy beforehand.