The best free Mac cleaner tells you what it deletes.

What a Mac cleaner should do

Modern Macs use APFS on an SSD. There's nothing to defragment, macOS manages its own memory and caches, and a Mac with 100 GB free runs the same as one with 300 GB free. Free space only matters when it's nearly gone.

So a good cleaner does three things:

• Explains every item. “2.1 GB of caches” isn't enough. You should know which app made them and whether they rebuild.
• Lets you undo. Files go to the Trash, not straight to oblivion.
• Uses Apple's tools for system files. Local snapshots, simulators, and the Spotlight index each have their own command. A cleaner should run those, not delete folders under /private/var.

What it can't promise

The category loves two phrases: “speed up your Mac” and “remove junk.” On an SSD, clearing caches doesn't make a Mac faster; the next launch of each app is usually a little slower while its cache rebuilds. And much of what gets cleared is your apps' working files. Clear space because you need the room, not for a promised performance gain.

The 6 best free Mac cleaners

“—” means we couldn't confirm it from the vendor's own materials as of October 2026.

1. Disk Forecast

Free, source available, for macOS 14 or later. It shows free space in the menu bar and, after 3 days of history, when your disk will be full. Its cleanup list sorts what it finds into “Safe to clear,” like caches, logs, and old build folders, and “Worth a look,” like big downloads, AI models, and virtual machines. Every item has a one-line explanation, and everything goes to the Trash. Its System Data window explains snapshots, simulators, and the rest, and runs Apple's own tool for each fix after showing you the command. It doesn't draw a treemap, uninstall apps, or find duplicates.

2. GrandPerspective

A free treemap of any folder or drive: every file a rectangle, sized by its space. It's open source under the GPL, updated in September 2026 for macOS 14 and later, and native on Apple silicon. It's free from its website, or $2.99 on the Mac App Store. It shows sizes, not meanings. GrandPerspective compared.

3. OmniDiskSweeper

The Omni Group's free column view of folder sizes, largest first, with a button to send what you pick to the Trash. It's quick to learn. Version 1.11 dates from 2018 and contains Intel code only, so on Apple silicon it runs through Rosetta 2. OmniDiskSweeper compared.

4. Mole

A free, open-source command-line cleaner by tw93, licensed under GPL-3.0. One command, mo, cleans caches, uninstalls apps, explores disk usage, and shows live system stats, with a --dry-run preview for anything that deletes. Note that mo purge deletes permanently. A separate Mac app costs $19. Mole compared.

5. AppCleaner

From FreeMacSoft, free with a donation option. Drop an app on its window, and it finds the files that app left around your Mac so you can remove them together. It's an uninstaller, and a good one. Version 3.7 needs macOS 15 or later.

6. Storage settings in macOS

Already on your Mac: System Settings › General › Storage. It sorts your disk by category, lets you delete large files and old iPhone backups, and offers a few recommendations. It can't tell you what's inside System Data; the System Data guide covers that.

Paid cleaners, briefly

CleanMyMac is MacPaw's suite of cleanup, malware scanning, and app tools, from $39.99 a year or $89.99 once. Is CleanMyMac safe? covers what it deletes and what it costs. DaisyDisk is a $9.99 analyzer that draws your disk as rings.

How to choose

• You want a warning before the disk fills: Disk Forecast.
• You want to see a whole drive at once: GrandPerspective.
• You live in Terminal: Mole.
• You're removing an app: AppCleaner.