What are junk files on a Mac?

Files your Mac no longer needs: caches, logs, crash reports, old installers and downloads, outdated device backups, temporary files and leftovers from apps you deleted.

Is it safe to delete junk files on Mac?

Yes, if you stick to user caches, logs, downloads and backups you recognise, and move them to the Trash rather than deleting them permanently. Never delete from /System or your Keychains folder.

How do I clean junk files on Mac for free?

Manually with Finder and Storage settings, or with a free tool. MacDiskCleaner’s free tier scans everything and cleans up to 2 GB in total at no cost.

How often should I delete junk files?

Every month or two for most people, or whenever you get a low-storage warning. Junk regenerates, so there’s no benefit in cleaning daily.

How to Delete Junk Files on Mac (Free, Manual and Automatic)

What counts as junk on a Mac, where it hides and how to delete it safely — caches, logs, old downloads, backups and app leftovers.

“Junk” on a Mac isn’t one folder. It’s a mix of temporary data that apps and macOS create and rarely clean up. Here’s where it lives and how to remove it without breaking anything.

Where Mac junk files hide

Junk	Where	Safe to remove?
App caches	`~/Library/Caches`	Yes — quit the app first
Logs and crash reports	`~/Library/Logs`	Yes
Old downloads and installers	`~/Downloads`	Yes, once you’ve checked them
iPhone/iPad backups	`~/Library/Application Support/MobileSync/Backup`	Old ones, yes
Mail attachments	`~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads`	Yes — they stay in the emails
Developer caches	`~/Library/Developer`, `~/.npm`, `~/.gradle`	Yes — tools rebuild them
Leftovers from deleted apps	`~/Library/Application Support`, `~/Library/Containers`	Yes, for apps you no longer have
The Trash	`~/.Trash`	Yes — that’s what it’s for

Downloads, device backups and developer caches are usually the biggest; caches and logs add up over time.

Option 1: Clean junk files manually

1. Clear app caches and logs

Quit your apps. In Finder press ⇧ ⌘ G, open ~/Library/Caches, and move the folders of apps you use heavily to the Trash. Do the same in ~/Library/Logs. Apps recreate what they need.

2. Empty your Downloads folder

Sort Downloads by size and delete installers (.dmg, .pkg, .zip) for apps you’ve already installed, plus files you’ve already saved elsewhere.

3. Delete old device backups

Connect your iPhone or iPad, select it in Finder and click Manage Backups — or remove old backup folders from the MobileSync path above.

4. Remove leftovers from deleted apps

Look in ~/Library/Application Support and ~/Library/Containers for folders named after apps you no longer have.

5. Empty the Trash

Press ⇧ ⌘ ⌫. Nothing is freed until you do.

Do it in one scan with MacDiskCleaner

Finds junk, duplicates and large files across your Mac, shows everything for free, and moves what you choose to the Trash first — so nothing is lost by mistake.

Version 1.1.2 · 4.8 MB · macOS 14 or later · Apple Silicon & Intel

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Option 2: Use a junk cleaner

A cleaner does the same thing faster, and shows you sizes before you decide. Look for one that:

Shows every item with its path and size before deleting.
Moves files to the Trash instead of erasing them.
Skips system files automatically.
Doesn’t run constantly in the background.

MacDiskCleaner’s cleanup scan covers caches, logs, old downloads, developer caches and app leftovers in one pass. Scanning is always free and you can clean up to 2 GB in total at no cost — here’s the free tier.

Things that look like junk but aren’t

Language files inside apps — removing them breaks the app’s code signature on modern macOS. Leave them.
/System/Library/Caches — protected and managed by macOS.
Purgeable space — macOS frees it automatically when needed.
Your Photos library — it can be huge, but it’s your photos. Use the Duplicates album instead of deleting the library.

Is it safe?

Yes, when you stick to the locations above and keep things in the Trash until you’re sure everything still works. Avoid any tool that wants to delete system files, “optimise memory” or clean daily — macOS handles those jobs itself.

How often should you clean junk files?

Every month or two is plenty for most people. If you’re a developer or edit video, check more often — build caches and render files grow quickly.