SSD Running Out of Space? How to Free Up or Expand Storage on Your Computer

When an SSD is nearly full, you may see failed updates, slow saves, or low-storage warnings. The fix usually has three stages: find what is using the space, remove or move what you don't need on the drive, and add storage if cleaning isn't enough. This guide covers all three for Windows and Mac, starting with the safest steps. For a related guide, see Can't Empty Trash or Recycle Bin? How to Fix Locked or Corrupt Files.

As a rough guide, try to keep around 10–20% of the drive free. That isn't a hard rule, but SSDs tend to perform better with some free room, and operating systems need space for updates and temporary files.

Step 1: See what is actually using the space

Deleting at random wastes time. Start with the built-in storage view.

• Windows 11 or 10: open Settings > System > Storage. The category breakdown (Apps, Temporary files, Documents, Videos, and so on) shows where to look first.
• macOS Ventura or later: open System Settings > General > Storage. On older versions, choose Apple menu > About This Mac > Storage > Manage.

For a closer look at individual folders on Windows, a free disk-usage tool such as WinDirStat or WizTree maps the largest files. You can also type size:>1GB into the File Explorer search box to list files over 1 GB.

Step 2: Free up space on Windows

Work through these in order, from lowest risk to highest impact.

1. Clear temporary files. In Settings > System > Storage, select Temporary files. Review the checked items before removing them. The Recycle Bin and Windows Update cleanup files are normally safe to clear. The list may also include your Downloads folder, so don't tick that unless you've checked it for files you want.
2. Turn on Storage Sense. In the same Storage page, enable Storage Sense so Windows clears temporary files and old Recycle Bin items automatically. On Windows 11, Cleanup recommendations also flags large or unused files.
3. Uninstall unused apps and games. Go to Settings > Apps > Installed apps (Windows 10: Apps > Apps & features) and sort by size. Games are often the biggest items. If you use Steam, you can move games to another drive in Steam > Settings > Storage instead of uninstalling them.
4. Run Disk Cleanup for system files. Search for Disk Cleanup, select your C: drive, then choose Clean up system files. This can remove old Windows Update files. It may also list Previous Windows installation(s) (the Windows.old folder), which can be several gigabytes. Deleting it means you can no longer roll back to the previous Windows version, so only do it once the current version is working well.
5. Free space from cloud-synced files. If you use OneDrive, right-click a synced file or folder and choose Free up space. The file stays in the cloud and shows as online-only. Make sure syncing has finished first, and remember you'll need an internet connection to open those files.

Optional: the hibernation file (hiberfil.sys) can take a noticeable amount of space. Running powercfg /hibernate off in an administrator Command Prompt removes it, but also disables hibernation and Fast Startup. Reverse it with powercfg /hibernate on.

Don't manually delete files in C:\Windows, such as System32 or WinSxS, and avoid "registry cleaner" or "PC booster" tools. They rarely free meaningful space and can break the system.

Step 3: Free up space on a Mac

In General > Storage, macOS offers recommendations that vary by version. Depending on yours, you may see:

• Store in iCloud for Desktop, Documents, and Photos. This moves files to iCloud and keeps placeholders on the Mac. It only works if you have enough iCloud storage, and you should confirm uploads have finished.
• Optimize Storage, which can remove watched Apple TV items and older email attachments from the Mac.
• Empty Trash Automatically, which deletes items that have been in the Trash for 30 days.
• Reduce Clutter, which lists large files and downloads for review.

Also look at the category list (Applications, Documents, iOS Files if present). Large old iPhone or iPad backups and unused apps are common culprits. Emptying the Trash is what actually reclaims space, so do that after deleting.

Step 4: Move large files without losing them

Photos, videos, game libraries, and old projects are usually better off on an external SSD or hard drive, or in cloud storage. Copy them first, open a few files from the new location to confirm they work, and only then delete the originals. Ideally, keep a second backup of anything irreplaceable. A single external drive is one failure away from losing everything on it.

Step 5: Expand storage when cleaning isn't enough

If you've cleared the obvious items and the drive is still tight, you have two main options.

Add an external drive

This is the simplest route and works on nearly any computer. A USB external SSD is fast enough for documents, media, and many games. It's best for files you don't need on the internal drive every minute of the day.

Replace or add an internal SSD

This depends entirely on your model, so check before buying anything.

• Many Macs, especially recent MacBooks, use storage that can't be upgraded by the owner. Check Apple's support information for your model before assuming otherwise.
• Many thin Windows laptops have a replaceable M.2 SSD, but some have soldered storage. Others use a different size or interface (SATA vs. NVMe, or a shorter M.2 length). Look up your exact model's specifications or service manual on the manufacturer's site.
• Desktops often have a spare M.2 slot or SATA connection, so adding a second SSD is usually easiest there.

Before opening a device, back up your data and note that opening it may affect warranty terms. If the drive is encrypted with BitLocker or Device Encryption, save your recovery key first (from your Microsoft account or wherever you stored it). To move your system to a larger drive, use the cloning tool offered by the SSD maker or a reputable cloning program, then confirm the new drive boots before wiping the old one. If you're not comfortable with this, a repair shop can do it.

If the problem persists

• Space didn't increase after deleting files: empty the Recycle Bin or Trash, then restart. Both can hold deleted files and keep them counted as used.
• Windows C: drive is full but folders don't add up: hidden system data may be responsible, including restore points. Search for Create a restore point, select your system drive, choose Configure, and review the maximum disk space it can use. Lowering it reduces how many restore points are kept, which is a tradeoff.
• Mac "System Data" is huge: restart, install any pending macOS updates, and check again. You can't safely delete system data by hand. If it stays unexplained, ask Apple Support to review it with you.
• C: is small but another partition has free space: open Disk Management to check. Extending C: generally needs unallocated space directly next to it, so back up before changing partitions.
• Computer won't update or boot because the drive is full: if you can still reach the desktop, free space first. If not, use manufacturer or Microsoft/Apple recovery options and avoid repeated forced shutdowns.

Check that it worked

Return to the Storage page and confirm free space has risen. Then restart, run Windows Update or macOS Software Update, and open a few key apps and files. If the drive still fills quickly after cleanup, look for a runaway source such as a growing cloud-sync folder, game library, or video project folder.

What to do next

Start with the storage breakdown, clear temporary files, and move large media off the drive. If you still can't stay comfortably below about 80–90% full, an external SSD is the easiest upgrade, and an internal swap is worth considering only after you've confirmed your model supports it.