How to clean /var/cache?

Method 1:

sudo apt-get autoclean
sudo apt-get autoremove

Method 2:

Launch your bleachbit as root user : no space in disk; sudo apt-get clean not working

Polipo, a web caching program may store a lot of data in an on-disk cache.

One way to clear this up is to issue the command sudo polipo -x - this will cause polipo to clear the local disk cache.

The most powerful of all commands to clean the cache for command line users is of course

sudo apt clean

Which will also delete all the cached files.