Are Mac cleaner apps safe, or a scam?

Short answer: mostly yes. A Mac cleaner from a reputable developer, one that's Apple-notarized and downloaded from the official source, is legitimate software, not a scam. So are Mac cleaners safe? The answer is that the category earned its bad reputation from two real things, and neither of them is the well-known app most people are actually asking about.

Where the "scam" reputation came from

Two things turned "Mac cleaner" into a dirty phrase. Both are real. Neither is the whole category.

The first is MacKeeper, the app that became the face of the problem. MacKeeper's original owner, ZeoBIT, settled a $2 million class-action lawsuit in 2015 over marketing that critics called scareware: warning of "serious" problems on a clean macOS install that only paying could "fix." The independent testing lab AV-Comparatives documented exactly that behavior on a brand-new system.

Those facts are dated, and worth stating as history rather than a present-tense verdict. The brand has since changed hands (it's now run by Clario) and rebranded. The point isn't that MacKeeper is a scam today; it's that this era is why a lot of people learned to distrust the words "Mac cleaner" at all.

The other real danger: counterfeits, not the famous apps

The second thing is fakes and PUPs (potentially unwanted programs). Security vendors do flag some cleaners as junkware, but look closely at which ones. Malwarebytes' published detections in this space name products like "Advanced Mac Cleaner" and "Mac Cleanup Pro", generic-sounding optimizers that nag you with scans. They do not flag CleanMyMac, the app most people mean when they ask the question.

The sharpest example is impersonation. In 2026, Malwarebytes documented a fake CleanMyMac website that pushed a stealer called SHub through a copy-paste Terminal trick. Malwarebytes was explicit that the counterfeit site was "unconnected to the legitimate software or the developers, MacPaw." The danger there wasn't the real app; it was a criminal wearing its logo. The lesson is old but it holds: download from the developer's own site or the Mac App Store, never from a search ad or a lookalike domain.

For the full breakdown on that specific app, see is CleanMyMac safe.

So, are Mac cleaners safe? Yes, but here's the honest catch

Even a legitimate, notarized cleaner has a catch, and it has nothing to do with malware. It's about what the app actually does, and how it reports it.

• The gains are usually temporary. Most of what a one-click cleaner clears is user cache. macOS rebuilds those caches the next time your apps run, and when your disk gets tight, Apple says macOS already clears safe-to-delete caches and logs on its own. So the space you "freed" often comes back, and some of it would have been reclaimed without you lifting a finger.
• The headline number is an estimate. That satisfying "12.4 GB of junk found" is a projection, not a measurement. macOS's own storage accounting is rough enough that experts call the System Data figure a "guesstimate". Anything built on top of it inherits that fuzziness. (More on why those numbers lie: why your Mac lies about free space.)
• One click can delete something you wanted. This is the real safety issue. A tool that batch-deletes on a single button, without letting you review each item, is trusting a heuristic to guess right every time. When it guesses wrong, flagging a file you meant to keep as "junk", the burden lands on you.

None of that makes a cleaner a scam. It makes the case for two habits: review before you delete, and treat any "freed" number with suspicion unless the tool actually measured it.

How to tell a safe cleaner from a sketchy one

• Notarized and signed by a named developer: it launches without Gatekeeper warnings.
• Downloaded from the official source: the developer's own domain or the Mac App Store, not an ad or a search result.
• Shows its work: exact files and paths, not just a spinning "cleaning…" animation and a big number.
• Lets you review before anything is deleted, item by item.
• Doesn't manufacture urgency: no red "your Mac is at risk!" banners on a perfectly healthy machine.

And the honest prior question is whether you need one at all. macOS handles most routine housekeeping itself, so for a lot of people the answer is no; see do you need a Mac cleaner.

The trustworthy end of this category has one thing in common: it shows you what's there and lets you decide. That's the line Plumby is built on. It measures the bytes it actually removes instead of estimating them, shows the exact path of everything before it touches a thing, and never goes near your documents, photos, or projects. A cleaner should make your Mac easier to trust, not ask you to trust it blindly.