How to clear out the Other category from iMac HD?

“Other” storage on Mac is files that don’t easily fall into the defined categories of “Audio" “Movies” “Photos” “Apps” and “Backups”. The types of files found in “Other" would include: 

• macOS system files

• Temporary files

• App plugins and extensions

• Browser and Mail caches

• Documents like .pdf, .psd, .doc,

• Disk images and archives like .dmg, .tar, .zip

You cannot directly manage the contents of this category. That is done by macOS, and the category varies in size depending on the current state of your Mac.

What you can do...

• Empty the Trash in the Dock.

• Empty the trash in the Photos app.

• Delete unused and unneeded installers from your downloads folder and desktop.

• Transfer files that you don’t use daily to an external drive. Files that take up the most room are movies, images and music.

• Force Time Machine to delete local snapshots:

https://support.apple.com/en-us/HT204015

This from Apple on the subject of storage management:

https://support.apple.com/en-us/HT206996

And this for a better, more thorough explanation:

What is “Other” and what can I do about it? - Apple Community (Kappy)

Forget about the Other category, what you need to do is to move large libraries which typically are:

• Photos
• Music
• Movies

all onto an external HD. The process is the same for each category, Apple explains in Move your Photos library to save space on your Mac - Apple Support how to do Photos and you use the same process for your music and movies libraries. Once done you can test them by double clicking each library and that will launch the app. For example double click the Photos library on the EHD and the Photos app will launch.

The next step is to free up the space on your internal drive by Trashing the 3 libraries stored on your internal drive and then emptying the Trash.

NEVER EVER let your internal drive get about 80-85% total capacity otherwise you can brick your Mac!!!!

Buy yourself a high quality EHD such as a OWC Mercury Elite Pro. These are reasonably priced, extremely reliable and you can upgrade the HD very easily!