How to Clear Cache and Free Up Storage on Mac

We cleaned out a MacBook Air with 256GB of storage last week. It was showing 14GB free, which is dangerously close to the “your Mac is literally going to start refusing to save files” zone. After 20 minutes of targeted cleanup — no third-party apps, no subscription tools — we freed up 47GB. Nearly a third of the entire drive.

The secret isn’t some hidden macOS trick. It’s that caches, logs, old backups, and forgotten downloads pile up silently, and macOS does a terrible job of telling you what’s eating your space. Here’s exactly where to look.

First: See What’s Using Your Storage

Before deleting anything, understand the landscape:

1. Click Apple menu () → About This Mac.
2. Click More Info → scroll down to Storage (or click Storage Settings).
3. Wait for the bar to finish calculating.

You’ll see categories like System Data, Documents, Apps, and Others. The frustrating part: macOS’s storage breakdown is famously unhelpful. “System Data” is often the biggest category, and Apple won’t tell you what’s in it. That’s where manual investigation comes in.

Clear Browser Cache

This is the easiest win. Browsers cache aggressively, and if you’ve never cleared yours, you might be sitting on 5-10GB of cached web data.

Safari

1. Open Safari → Settings (Cmd + ,) → Privacy tab.
2. Click Manage Website Data.
3. Click Remove All.

Alternatively, enable the Develop menu (Settings → Advanced → Show Develop menu) and click Develop → Empty Caches.

Chrome

Chrome is the bigger offender here. It caches more aggressively and creates separate profiles for each Google account.

1. Open Chrome → Settings → Privacy and security → Delete browsing data.
2. Select All time as the time range.
3. Check Cached images and files. Uncheck everything else unless you want to nuke your cookies too.
4. Click Delete data.

For a deeper clean, navigate to ~/Library/Application Support/Google/Chrome/Default/Service Worker/CacheStorage/ and check the size. We’ve seen this folder hit 3-4GB on its own.

Clear System Cache

macOS stores caches in two locations:

User Cache

1. Open Finder.
2. Press Cmd + Shift + G (Go to Folder).
3. Type ~/Library/Caches and press Enter.
4. You’ll see folders named after apps — com.apple.Safari, com.spotify.client, etc.
5. Don’t delete the folders themselves. Open each folder and delete the contents. Deleting the parent folder can confuse some apps.

System Cache

Same process, but navigate to /Library/Caches (without the ~). You’ll need to authenticate with your admin password to delete items here.

Realistically, user caches are where the bulk of reclaimable space lives. System caches are usually small and actively used. Focus on user caches.

How much will this save?

On a Mac that’s been used daily for a year without cache clearing: typically 3-8GB. Not life-changing on a 1TB drive, but on a 256GB MacBook Air or MacBook Neo, that’s significant.

Empty the Trash (Seriously)

This sounds insulting, but we have to say it. The Trash on macOS doesn’t auto-empty by default. Every file you’ve ever “deleted” by pressing Cmd + Delete is sitting in the Trash folder, taking up real space.

Right-click the Trash icon in your Dock → Empty Trash.

If you want it to auto-clean: System Settings → General → Storage → Empty Trash Automatically (after 30 days). Turn this on and forget about it.

Remove Old iOS/iPadOS Backups

If you’ve ever backed up an iPhone or iPad to your Mac, those backups are still there. And they’re enormous — typically 10-50GB each.

1. Open System Settings → General → Storage.
2. Look for iOS Files or navigate manually: ~/Library/Application Support/MobileSync/Backup/.
3. Delete backups for devices you no longer own. Keep the most recent backup for current devices if you prefer local backups over iCloud.

This is the single biggest space saver for most people. We’ve seen Macs with 3-4 old iPhone backups totaling over 100GB. Insane.

Find Large Files Hiding in Downloads

Your Downloads folder is probably a graveyard:

1. Open Finder → Downloads.
2. Switch to List View (Cmd + 2).
3. Click the Size column header to sort by file size.
4. Delete the DMG installers, ZIP files, and PDFs you downloaded once in 2024 and never opened again.

A faster approach: use the built-in storage tool. Go to System Settings → General → Storage and click the (i) next to Documents. Sort by File Size and filter to Downloads. You’ll find things you forgot existed.

Delete Xcode Derived Data (Developers Only)

If you’ve ever installed Xcode — even once, even just to get command-line tools — check these locations:

• ~/Library/Developer/Xcode/DerivedData/ — build artifacts. Can grow to 20-50GB.
• ~/Library/Developer/Xcode/Archives/ — old app archives.
• ~/Library/Developer/CoreSimulator/Devices/ — iOS Simulator data. Easily 10-30GB.

You can safely delete everything in DerivedData. Xcode will rebuild what it needs. Archives and Simulators are less critical — delete old ones you don’t need.

Non-developers: if you see Xcode taking up 35GB in Storage Settings and you don’t code, just delete the entire app. You probably installed it by accident or for a one-time thing.

Use macOS Optimize Storage

Apple built some decent cleanup tools right into the OS. Go to System Settings → General → Storage and review:

• Store in iCloud — moves old files to iCloud and downloads them on demand. Only useful if you’re paying for iCloud storage.
• Optimize Storage — auto-removes watched Apple TV+ content and old email attachments.
• Empty Trash Automatically — 30-day auto-clean.

The “Recommendations” section here sometimes surfaces large files or folders you’ve forgotten about. Worth checking once.

What NOT to Delete

A few critical warnings:

• Don’t delete anything in /System/Library/. Ever. That’s the operating system.
• Don’t delete ~/Library/Application Support/ folders unless you know what the app is and you’re sure you don’t use it. Many apps store their databases here.
• Don’t delete .Spotlight-V100 folders. That’s your search index. Deleting it forces a full re-index that takes hours and makes your Mac hot.
• Be cautious with ~/Library/Containers/. These belong to sandboxed apps. Deleting a container effectively erases that app’s data.

When in doubt, move the folder to your Desktop instead of deleting it. Use your Mac for a week. If nothing breaks, delete it from the Desktop. This cheap insurance has saved us more than once.

The Quick Cleanup Checklist

If you just want the fast version, do these five things in order:

1. Empty Trash — 30 seconds, potentially huge gains
2. Delete old iOS backups — 2 minutes, 10-50GB recovered
3. Clear Downloads folder — 3 minutes, 5-20GB
4. Clear browser cache (Safari + Chrome) — 2 minutes, 3-10GB
5. Clear ~/Library/Caches contents — 5 minutes, 3-8GB

Total time: about 15 minutes. Expected recovery on a 2-year-old Mac: 20-50GB. That’s real space — enough to stop those annoying “Your disk is almost full” warnings and keep your Mac running smoothly for months.