how to manage obsolete branches on github

I usually develop new features of my codes in dedicated branches, then merge them to master.

The problem with this is that after some time I have a lot of obsolete bra开发者_运维百科nches that are cluttering the github interface, where there might be instead branches which are actively developed.

Is there a way to archive them somehow, or should I just delete them, as the commits have already been merged?

If you have already merged branches and have no need to develop on them anymore, then it's safe to delete them. You don't loose any commit, as they have been merged and are now stored in master.

I would only propose to leave branches you actively develop