How to Free Up Disk Space on a Mac (and See What You Can Get Back First)

“System Data” and “Other” in macOS storage settings tell you almost nothing. You know the disk is nearly full, but not which folder to open.

Spotless is built around that gap: it scans first and shows you the whole bill before it asks for anything.

The short version

1. Open Spotless and run a scan. It covers junk and caches, duplicate files, similar photos, large files, developer clutter and app leftovers in one pass.
2. Look at the totals per category. Every file and size is visible, even on the free version.
3. Open the category you care about and read the list. Untick anything you want to keep.
4. If the number is worth it, unlock cleaning and remove the selected items.

What a scan actually looks at

• Caches, logs and crash reports. Old, rebuildable files that apps leave behind. Package-manager leftovers from npm and Homebrew are included.
• Developer clutter. Xcode DerivedData, archives, device support files and module caches. If you build apps, this is often the single biggest item.
• Duplicates. Files with identical content, grouped together. Names don’t matter.
• Similar photos. Burst shots and “same frame, six tries” sets.
• Large files. Your biggest files sorted by size, so a forgotten disk image or video export stands out.
• App leftovers. Support files from apps you deleted a long time ago.

What happens before anything is deleted

You see the file list. That is the safety net, so use it. A cache is safe to lose because the app rebuilds it. A duplicate or a large file is your file, and only you know if it matters.

Which version can reach what

The direct download and the App Store version don’t reach exactly the same places. System-wide caches and the Trash, for example, are only available in the direct download. See App Store vs. direct download before you choose.

Tips

• Start with developer clutter and caches. They regenerate, so there’s little to regret.
• Treat duplicates and large files as “review”, not “select all”.
• Run a scan every few months. It takes minutes, and it’s free.

FAQ

Do I have to pay to see what Spotless found? No. Scanning is free and unlimited, and the results are never blurred. You see every file and size. Removing things is what needs an unlock.

Will it delete things without asking? No. You review the file list before anything is removed, and rules are checked against a safety list.

How much space will I get back? It depends on the Mac. Developers with old Xcode data tend to get the most, because build caches can run into tens of gigabytes. Run a scan and you’ll see your own number.