How can I clean up my user Library folder?
Solution 1:
As usual for cleanup stuff, start with a visualizer like GrandPerspective or Disk Inventory X so you can see what folders take up space.
Be careful deleting stuff in your Library folder: apps store lots of different things in there, some of which are required for them to run.
Solution 2:
Your Library folder contains several things which may be quite large: all your mails (including attachments), various caches, databases of some applications (e.g. Evernote) etc., so the big size might be ok (or even desired!).
To identify the big stuff you can open Terminal.app and run
cd ~/Library
du -sm * | sort -n
which will show you the largest directories at the end. Use cd again to drill further done and repeat the du
command.
PS: Just for reference: My Library folder currently holds about 16 GB of Evernote data, 4 GB Developer docs from Xcode, 1 GB mail and 1.5 GB iOS software updates.
Solution 3:
You could also enable calculating all sizes and sort by size in list view:
To let that right window appear, use command ⌘ + J in Finder.
You can also reach this window by clicking on "Show View Options" within "View" in your menu bar. Note that this window changes depending on showing the directory as icons, as list, as columns or as cover flow. So be sure to view "as list".
Solution 4:
For Developers:
~/Library/Developer/Xcode/DerivedData
directory can become pretty large after some time of creating different projects. You can easily delete all the directories with age a week and higher.
~/Library/Developer/Xcode/Archives
same story here, but you need to be more careful with removing old archive files (especially if your projects are not under version control).
By my experience archive folder for an app can become really huge as developers usually create lots of versions of same app before its public releases. I believe it's better to clean this folder from XCode by going through all your old archives and removing the ones you don't need. The best scenario is that you have commented each archive during your work. On the other hand, if you didn't, most probably it won't make too much sense to keep old archives when you don't know what those are about.
I cleaned about 300GB only from above directories (2 years those were out of my attention).