How to check storage on Mac and see what uses the space

1. Open Storage settings

Apple’s guide gives the path: choose Apple menu → System Settings, click General in the sidebar, then click Storage. On macOS versions before Ventura, Apple’s storage page points to Apple menu → About This Mac → Storage instead. The steps are the same on a MacBook Air, MacBook Pro, iMac or Mac mini.

Give the screen a minute. The bar appears immediately but the categories keep refining while macOS finishes counting, so the first numbers you see can shift before they settle.

2. Read the bar

Apple describes the coloured bar as the storage used by different apps and file types, with the amount of free storage shown as Available. Hover over a segment to see its name and size. The categories are macOS’s classification, not folders: a file counts once, under whichever category fits it best.

Two segments confuse most people. System Data is Apple’s catch-all for files that fit no other category, which its guide says primarily includes system files such as logs, caches and runtime resources. Available can include purgeable space that macOS has not released yet, which Disk Utility separates from free space. The related guides cover both in detail.

3. Open a category with its information button

Apple’s guide notes that categories such as Applications, Documents, Messages, Mail, iOS files and Trash have an information button that opens them. This is where the useful lists live.

• Applications: every app sorted by size, with a column showing where it came from and whether it is still supported.
• Documents: three views, Large Files, Downloads and a File Browser, each sortable by size with a Show in Finder option.
• Messages and Mail: attachments by size, deletable from the list. The Mail and Messages guides explain what deleting does to your accounts.
• iOS files: iPhone and iPad backups stored on the Mac, with their dates.
• Trash: what is waiting to be emptied, and how much space emptying it returns.

4. Check a single disk or an external drive

Storage settings describes the startup disk. For any volume, open Disk Utility, select it and read the capacity, used and available figures; Apple’s Disk Utility guide explains that available can include both free space and purgeable space. In Finder, select a drive and choose File → Get Info for the same numbers.

External drives keep their own Trash, so a drive that looks full after you deleted files needs its Trash emptied while it is connected. The Trash guide covers the cases where that refuses.

5. See what the categories hide

System Data has no information button and no list, which is the point where Storage settings stops helping. The next layer is the folders themselves: the Library guide explains what is in there, the Terminal guide gives the read-only commands that size every folder, and the large-files guide covers documents that Storage settings misses because they sit outside your home folder.

A disk scanner does the same in one pass, with allocated sizes and a label for each folder. ClearDisk’s scan is free and local, shows the System Data folders Storage settings only totals, and lets you reveal any item in Finder before deciding what to do with it.

Common questions about Mac storage

The questions people ask alongside this one, answered briefly.

• How do I free up space on my Mac? Start with the clear-storage guide: empty the Trash, clear Downloads, use Apple’s recommendations, then review large files and System Data.
• How do I check available storage? System Settings → General → Storage shows Available at the top of the bar; Disk Utility shows the same volume with free and purgeable space separated.
• How many GB does my Mac have? Choose Apple menu → About This Mac and click More Info, then Storage, or open Disk Utility and select the startup volume; the capacity shown there is the full size of the disk.
• Why is my Mac storage still full after deleting? Space returns only when the Trash is emptied, and Storage settings can lag; purgeable space and local snapshots can also hold the figure for a while. The storage-not-updating guide covers each case.