Where to find your storage information

Your MacBook Air stores information about how much disk space you have used in the System Settings app. Open System Settings from your Applications folder or by clicking the Apple menu in the top-left corner and selecting System Settings. Then click General in the left sidebar, and select Storage. This screen shows you a visual bar of your total storage capacity and how much space each category is using.

The storage breakdown appears as colored blocks: System (the operating system itself), Apps, Photos, Documents, Mail, Trash, and Other. Each block shows roughly how much space that category occupies. The total capacity of your MacBook Air appears at the top — common sizes are 256GB, 512GB, or 1TB. Below that, you see how much space is available right now.

Key Takeaways

  • Open System Settings, click General, then Storage to see your disk space usage broken down by category.
  • The colored bar at the top shows your total capacity and how much space is used versus available.
  • Click any category in the storage list to see which individual files or apps are taking up the most space.
  • If you have less than 10GB available, your MacBook Air will slow down and you should delete files or move them to external storage.
  • The "Other" category often contains cache files and temporary data that you can safely remove using the Finder or third-party tools.

Understanding what each storage category means

The System category includes macOS itself — the operating system that runs your MacBook Air. This typically uses 15GB to 25GB depending on which version of macOS you have installed. You cannot remove this without reinstalling the operating system, so do not try to delete it.

Apps shows the total size of all your installed applications. Clicking on Apps lets you see individual app sizes and uninstall the ones you no longer use. Mail includes all your email messages and attachments stored locally on your machine. Photos contains your photo library if you store it on your MacBook Air rather than in iCloud. Documents, Desktop, and Downloads are grouped together and show files you have saved in those locations.

The Other category is a catch-all for cache files, temporary data, system logs, and files the system cannot easily categorize. This can grow large over time but much of it is safe to delete. Trash shows files you have deleted but not permanently removed — emptying the Trash frees up this space immediately.

Drilling down into specific categories

Click on any category in the storage list to see a detailed breakdown of what is using space. For example, clicking Apps shows every installed application sorted by size, with the largest apps at the top. This helps you identify which apps are taking up the most room — video editing software, games, and design tools often use several gigabytes each.

Clicking on Documents, Desktop, or Downloads shows a folder view where you can see individual files and folders. Large video files, old project folders, or duplicate downloads often hide here. You can delete files directly from this view by right-clicking and selecting Move to Trash, or by selecting the file and pressing Command+Delete.

For the Other category, click it to see what files are included. Many of these are system files you should not delete, but you can identify large cache files or old temporary folders. If you see a folder labeled Caches or Logs, these are usually safe to delete, though your system will recreate them as needed.

When your storage is running low

If your available storage drops below 10GB, your MacBook Air will begin to slow down noticeably. The system needs free space to create temporary files while running apps and performing updates. When space is critically low, you may see warnings that your startup disk is almost full, and some apps may refuse to run or save files.

Start by emptying the Trash if you have not done so recently — this is the fastest way to free up space. Then look for large files you no longer need: old video projects, duplicate photos, or archived downloads. Moving files to an external hard drive or USB stick is a good option if you want to keep them but need space on your MacBook Air.

If you use iCloud Photos, you can enable Optimize Storage in System Settings to keep only thumbnails on your MacBook Air while storing full-resolution photos in iCloud. This can free up 10GB to 50GB depending on how many photos you have. Similarly, if you subscribe to iCloud+, you can move Documents and Desktop folders to iCloud to free up local space.

Checking storage without opening System Settings

You can also check storage by opening Finder, clicking on your MacBook Air name in the sidebar (usually "Macintosh HD"), and looking at the bottom of the window. A bar appears showing used space in different colors and available space in white. This gives you a quick visual without opening System Settings, though it does not show the detailed breakdown by category.

Another option is to use the Activity Monitor app to see which running processes are using the most memory (RAM), though this is different from disk storage. Open Activity Monitor from Applications > Utilities, click the Memory tab, and sort by Memory to see which apps are consuming the most RAM. High memory usage can make your MacBook Air feel slow even if you have plenty of disk space available.

Moving files to free up space

If you have large files you want to keep but need space on your MacBook Air, connect an external hard drive or USB stick and drag files to it. Video files, photo libraries, and project folders are good candidates for moving. Make sure the external drive has enough space — check its capacity the same way you check your MacBook Air storage by clicking the drive in Finder and looking at the bottom bar.

Before you move or delete anything, make sure you have a backup. Time Machine is built into macOS and can back up your entire MacBook Air to an external drive automatically. If you have not set up Time Machine, do that first by going to System Settings > General > Time Machine and clicking Add Backup Disk. This way, if you accidentally delete something important, you can restore it from the backup.

Frequently Asked Questions

Why does my available storage show less than my total capacity minus what is being used?

The System category and Other category are larger than they appear because they include hidden files and system data. Also, your MacBook Air reserves some space for the operating system to function properly — typically 5GB to 10GB is always held in reserve and cannot be used for your files.

Is it safe to delete files in the Other category?

Some files in Other are safe to delete, like old cache files and temporary downloads, but others are system files you should not touch. If you see folders labeled Caches or Logs, those are generally safe. If you are unsure about a specific file, do not delete it — move it to Trash first so you can recover it if something breaks.

What should I do if I see a message that my startup disk is almost full?

This means you have less than 1GB to 2GB available. Empty your Trash immediately, then delete or move large files you no longer need. If that does not free up enough space, consider moving your photo library or documents to iCloud or an external drive. Restart your MacBook Air after freeing up space to ensure the system recognizes the new available storage.

Can I increase my MacBook Air storage after I buy it?

No, the storage in a MacBook Air is built into the logic board and cannot be upgraded or replaced by the user. You can only add external storage using USB drives, external hard drives, or cloud storage services like iCloud. If you are running out of space regularly, you may need to manage files more carefully or consider a MacBook Air with larger storage capacity if you upgrade in the future.

Does iCloud storage count toward my MacBook Air storage?

No, iCloud is separate cloud storage that does not use your MacBook Air disk space. However, if you download files from iCloud to your MacBook Air, those files do use local storage. You can see which iCloud files are stored locally by opening Finder, clicking iCloud Drive, and looking for files with a cloud icon — those are stored in iCloud only.