Where is the Mozilla Firefox cache located?

Solution 1:

Cache is the regular cache backend.
Cache2 is a new cache backend since Firefox 27 and onwards.
OfflineCache is the offline cache from which a resource is essentially loaded first and then it is checked if it is still fresh.
startupCache is a sort of fastload feature.

All of these are capable of holding pieces of website data.

Solution 2:

.mozilla/firefox directory contains the settings and extensions. Here's output of mine:

$ ls .mozilla/firefox/b1ygiwi1.default/ | head      
addons.json
addons.sqlite*
blocklist.xml
bookmarkbackups/
cert8.db*
cert_override.txt*
compatibility.ini*
content-prefs.sqlite*
cookies.sqlite*
cookies.sqlite-shm*

The other directory actually contains different types of cache, as wie5Ooma already mentioned.

So if something would be going wrong, you'd might want to try altering or deleting completely whatever is in ~/.mozilla/firefox/ to restore settings to default.

There is also cache in .macromedia/Flash_Player\#SharedObjects/ which belongs to flash player if you use that, like s.ytimg.com from youtube.

Solution 3:

This is my location for all stuff, including songs from sites .cache/mozilla/firefox/[random characters].default/cache2/entries