Which is the better location to compress images? In the browser or on the server?
I advice you to compress on the browser in order to :

avoid loading the server with many CPU and RAM heavy consuming calculations (as numerous as number of clients)
dwindle bandwith needed when transfert image threw the network
I have a Django project and i allow users to upload images. I don't want to limit image upload size for users. But want to compress the image after they select and store them. I want to understand which is better:

Compress using java-script on the browser.
Back end server using python libraries.

Also it will be helpful if links can be provided to implement the better approach.