Disk space analyzer for Mac

What your Mac already shows you

• Storage settings: System Settings → General → Storage sorts the disk into Applications, Documents, Photos, Mail and more, with an i button on each that lists the largest items. Whatever it cannot attribute lands in System Data, which is often the biggest bar and the least explained.
• Finder: open a folder in List view, choose View → Show View Options and tick Calculate all sizes, then sort by Size. It works one folder at a time and skips hidden ones such as ~/Library unless you go there with Go → Library.
• Terminal: the exact answer, including hidden folders.

du -xh -d 1 ~ 2>/dev/null | sort -h | tail -15
du -xh -d 1 ~/Library 2>/dev/null | sort -h | tail -15

The first line lists the fifteen largest folders in your home folder, the second the same inside your Library, where caches, app data and developer files live. Run them again inside whichever folder comes out on top, and in a few steps you have found it. Terminal may need Full Disk Access in System Settings → Privacy & Security to read some folders.

What a disk space analyzer adds

Analyzers such as DaisyDisk, GrandPerspective and OmniDiskSweeper do the same walk over the whole disk at once and draw it, as nested rings or blocks sized by bytes, or as a list you can open level by level. That makes a 40 GB folder you had forgotten about hard to miss, and most let you delete from the picture. For finding where the space went, they are quick and good.

The question an analyzer does not answer

A map shows that ~/Library/Developer is 60 GB, or that a folder in Application Support is 12 GB. It does not say whether deleting it costs you nothing, a rebuild, a re-download, or the only copy of something. Some of the biggest folders on a Mac are safe to clear and some are the opposite, and their names rarely say which. That judgement is left to you, one folder at a time.

Where the app comes in

RefreshYourMac measures by what a thing is rather than where it sits: caches, logs, Xcode and simulator data, package caches, AI tool downloads, duplicates, old installers and large files are each a category with its size, and each is rated by its safety levelfor what cleaning it would cost. By Size lists every category largest first, the way an analyzer would, with the rating beside it. Large Files picks out anything over 200 MB in Downloads, Desktop, Documents and Movies, and duplicates are matched on contents, never on the name. Nothing is deleted until you confirm. For the steps by hand, see how to free up space on a Mac.