Let macOS manage space between multiple volumes
Check Disk Space On Mac
Options for checking free hard-drive space in OS X. Running low on disk space can greatly slow down your computer. Here are several ways to look this up on your system. Another way to check the free storage on your Mac. Although the way shown above is the easiest way to check for how much storage space you have left on your Mac, it’s not the only way. Another way is to open a Finder window and go to your computer under the Locations list in the sidebar.
With Apple File System (APFS), the file system introduced in macOS 10.13, you can easily add and delete volumes on your storage devices. APFS-formatted volumes automatically grow and shrink—you never have to repartition a storage device again.
If Disk Utility reports “overlapped extent allocation” errors, two or more files occupy the same space on your disk, and at least one of them is likely to be corrupted. You need to check each file in the list of affected files. Most of the files in the list have aliases in a DamagedFiles folder at the top level of your disk.
Keep your external storage devices secure
When you get a new flash drive or other storage device, format it as APFS and encrypt it with a password to protect its contents.
How To Free Disk Space On Mac
Give your disk a checkup
If you’re having problems with a disk, Disk Utility can check the disk and repair problems it detects.
Check Disk Space For Mac Catalina
To browse the Disk Utility User Guide, click Table of Contents at the top of the page.