Reader Daniella tried to free up storage on her Mac after finding she only had 16GB available:
I decided to delete a lot of files in my MacBook Pro. I also emptied my Trash and restarted my laptop. However, when I checked my storage after deleting files, I saw that it didn’t increase my storage but it lessened to 14.87GB. How is that possible? What happened?
This is a multifaceted problem which I’ve written about in bits and pieces before. It could be a Spotlight indexing error. Spotlight produces the information that’s used in the > About This Mac > Storage display. You can delete and re-index your Mac.
Restarting a Mac should clear temporary caches that can grow during a continuous session (between restarts/shut downs). However, it’s possible that due to applications used and available memory, OS X or macOS will create larger caches at startup time to handle swapping active program memory to and from disk.
Now as to how to free up storage, if you’re running Sierra, it includes extensive help in optimizing storage, deleted unneeded files, and shifting data to iCloud. Check out our overview from last fall.
Whether in Sierra or earlier versions, you can create a Spotlight search (and store as a smart folder) that helps you figure out your largest files, and then decide whether you need to delete them.(The article continues...)