The Ultimate Guide to Cleaning and Optimizing Your MacBook Storage

Running out of storage on your MacBook can make everything feel sluggish—from opening apps to saving files. Over time, system junk, cache files, and duplicate data pile up, quietly eating away your precious gigabytes. This ultimate 2025 guide shows you how to clean and optimize your MacBook storage safely using both built-in tools and trusted third-party apps, no tech degree required.

Why Your MacBook Runs Out of Space

Everyday tasks like browsing, editing photos, and installing apps generate hidden files. macOS stores system logs, caches, and Time Machine snapshots automatically. These are useful—but they build up. Common storage hogs include:

• Large photo and video libraries
• Old downloads and disk images (.dmg files)
• System cache, browser cache, and app leftovers
• iOS or iPadOS backups
• Duplicate documents and media files

If your storage is 90% full, macOS may slow down because it lacks free space for virtual memory and temporary files.

Step 1: Check What’s Using Space

Start by getting a clear picture of what’s eating your storage.

Use macOS Storage Management

1. Click Apple Menu → System Settings → General → Storage.
2. Review the color-coded bar showing System, Apps, Documents, and Other.
3. Click “i” icons beside each category to explore details.
   You’ll quickly spot which areas—like videos, mail attachments, or system data—are using the most space.

Step 2: Use “Optimize Storage” Options

Apple’s built-in tools are a great first step for quick cleanup.

1. In System Settings → General → Storage, click Recommendations.
2. Enable:
   • Store in iCloud: Moves large files and photos online while keeping recent ones local.
   • Optimize Storage: Removes watched Apple TV movies and old email attachments.
   • Empty Trash Automatically: Deletes items after 30 days.
3. Review Reduce Clutter to manually inspect old documents.
   These options safely automate part of your cleanup without touching critical files.

Step 3: Remove Large and Unused Files

Go beyond recommendations by manually removing files you no longer need.

Use Finder Search

1. Open Finder → All My Files or press Command + F.
2. Filter by “File Size → Greater than 100 MB.”
3. Sort and review before deleting—be cautious with system folders.

Delete Old DMG Files

Disk image files (.dmg) from past app installs can take gigabytes. Search “.dmg” in Finder and remove them.

Step 4: Clean Up System and Cache Files

Caches speed up performance but can grow massive over time.

Clean Manually (Advanced Users)

1. Open Finder → Go → Go to Folder…
2. Enter: ~/Library/Caches and /Library/Caches.
3. Delete contents inside each folder (not the folder itself).
   Alternatively, use a reliable cleaner like CleanMyMac X, OnyX, or Sensei—these apps safely remove junk, logs, and old system files with a single click.

Step 5: Manage Photos, Videos, and iCloud

Photos and videos often occupy the largest share of storage.

Use iCloud Photo Optimization

1. Go to Photos → Settings → iCloud.
2. Check Optimize Mac Storage to store smaller versions locally.
3. Full-resolution originals stay in iCloud, freeing up gigabytes.

Use External Drives

Move old video projects or RAW photo files to an external SSD or HDD. This keeps your internal drive lean and fast.

Step 6: Delete Old Backups and Time Machine Snapshots

Local Snapshots

Time Machine creates hidden snapshots that can eat space.
Open Terminal and type:

tmutil listlocalsnapshots /

To delete them:

sudo tmutil deletelocalsnapshots <date>

Or simply connect your Time Machine drive—macOS will automatically clear old snapshots.

iOS and iPadOS Backups

1. Open Finder → Locations → Your Device.
2. Under “Manage Backups,” delete outdated ones.

Step 7: Manage Applications

Uninstall apps you no longer use completely.

Manual Method

Drag unwanted apps from Applications to Trash, then remove leftover support files:
~/Library/Application Support/
~/Library/Preferences/

Easier Method

Use AppCleaner (free) to uninstall apps with all their related files safely.

Step 8: Empty Trash and Mail Attachments

It’s easy to forget these hidden space hogs.

• Empty Trash manually from the Dock.
• In Mail, go to Mailbox → Erase Junk Mail and Erase Deleted Items.
• In Messages, delete old media-heavy conversations.

Step 9: Optimize Startup and Performance

If your Mac feels slow even after cleaning, too many startup apps might be the culprit.

1. Go to System Settings → General → Login Items.
2. Disable apps you don’t need launching at startup.
3. Restart your Mac to feel the difference.

Step 10: Use External or Cloud Storage

For long-term organization, consider hybrid storage management.

• External SSDs: Great for video editing or backups.
• Cloud Storage: Google Drive, Dropbox, or iCloud Drive integrate seamlessly with Finder.
• NAS (Network Attached Storage): Ideal for teams or multi-device backups.

Bonus: Automate Maintenance

You can schedule regular cleanup tasks to keep your Mac fresh.

• Use CleanMyMac X Smart Scan weekly.
• Run Disk Utility → First Aid monthly to fix drive errors.
• Enable Automatic macOS Updates for stability and security.

Final Thoughts

Cleaning and optimizing your MacBook storage isn’t just about reclaiming space—it’s about restoring performance and extending your laptop’s lifespan. By combining macOS’s built-in tools with smart manual cleanup and automation, you can keep your system running fast, smooth, and clutter-free throughout 2025.

FAQ

How often should I clean my Mac storage?
Every 2–3 months is ideal for regular users; heavy media users should check monthly.
Can I use third-party cleaners safely?
Yes, as long as they’re reputable (like CleanMyMac X or Sensei). Avoid random downloads.
Why does “System Data” take so much space?
It includes caches, logs, and local backups. Cleaning caches and snapshots reduces it.
What’s the fastest way to free up space quickly?
Delete old videos, downloads, and DMG files, then empty Trash.