System Data

There's no button that clears System Data, because it isn't a folder. Here's the order that actually shrinks it, safest first, using only the settings macOS already gives you.

Your Mac is quietly holding onto 100–200 GB you never chose to keep: cache, “System Data,” APFS snapshots, and files apps leave behind when you delete them. Here's what all of it actually is, and how to see it.

What is System Data on Mac? It's a catch-all storage category: a rough estimate, not a folder you can open. Here's what's in it and how to safely shrink it.

Why is my Mac storage full when you deleted everything? Because APFS snapshots retain old blocks, space stays purgeable, and 'System Data' won't budge.