How to Free Up Space on Your Computer

The fastest way to free space is to stop guessing: open your computer's built-in storage map, sort by size, and go after the three biggest offenders — leftover system files from Windows or macOS updates, apps you never open, and a Downloads folder you forgot existed. On a typical laptop that alone recovers 20-60 GB in under half an hour, without touching a single personal photo or document.

One thing worth knowing before you start: on an SSD (the flash storage in nearly every laptop sold since about 2018), you want to keep at least 10-15% of the drive free. SSDs slow down noticeably when they are almost full because the controller has less room to shuffle data, so freeing space is not just about fitting more in — it makes the machine faster too.

Start with the map, not the delete key#

Deleting files at random is how people lose things they needed while barely denting the problem. Both operating systems ship a storage breakdown that shows exactly what is eating your drive.

• Windows 11: Settings > System > Storage. The bar at the top splits your usage into Apps, Temporary files, Documents, Pictures, and more. Click any category to drill in.
• Windows 10: Settings > System > Storage, then "Show more categories."
• macOS (Ventura 13 and later): Apple menu > System Settings > General > Storage. On older macOS: Apple menu > About This Mac > Storage tab > Manage.

The reveal is almost always the same: people assume their photos are the villain, then discover the real weight is old app installers, cached video, virtual machine files, or system leftovers. Look at your largest categories first. Clearing one 20 GB folder beats an hour of tidying 5 MB files.

If the built-in view is too coarse, a free file-size mapper shows every folder scaled by how much room it takes. On Windows, WinDirStat or TreeSize Free are the standards; on macOS, GrandPerspective or DaisyDisk. These turn "somewhere on the drive" into a specific folder you can act on.

Windows: the biggest wins, in order#

Clear update leftovers with Disk Cleanup#

This is the single most overlooked source of wasted space on Windows. Every major update leaves behind old files, and they can quietly hold 15-30 GB.

1. Press the Windows key, type Disk Cleanup, and open it (or run cleanmgr).
2. Choose your C: drive.
3. Click Clean up system files — this is the important button most people skip. It reappears with new options.
4. Tick Windows Update Cleanup, Previous Windows installation(s) if present (the Windows.old folder, often 15-30 GB), Delivery Optimization Files, and Temporary files.
5. Click OK.

Note that Windows.old is your escape hatch to roll back to a previous Windows version, and Windows deletes it automatically after 10 days. If your recent update is stable, clearing it early is safe and frees the most space of any single action.

Turn on Storage Sense so it stays clean#

Storage Sense is Windows' automatic janitor. Go to Settings > System > Storage > Storage Sense and switch it on. Configure it to empty the Recycle Bin after 30 days and clear the Downloads folder of files older than, say, 30 or 60 days. From then on the clutter clears itself, which matters more than any one-time cleanup.

Uninstall apps by size — the right way#

Go to Settings > Apps > Installed apps (Windows 11) or Settings > Apps > Apps & features (Windows 10), then sort by size. Games, video editors, and creative suites are usually the heaviest — a single AAA game can be 80-150 GB.

Uninstall from this list, never by dragging a desktop icon to the Recycle Bin. That icon is only a shortcut; deleting it leaves the entire program installed and still taking space. If a name is unfamiliar, look it up before removing it — some entries are drivers or runtimes (like Microsoft Visual C++ Redistributable) that other software depends on.

macOS: where the space really goes#

Use the Storage recommendations#

In System Settings > General > Storage, macOS lists concrete recommendations: Store in iCloud, Optimize Storage (removes already-watched Apple TV downloads and old email attachments), and Empty Trash Automatically (clears items after 30 days). The scrollable list below breaks usage down by category — click the "i" next to Applications, Documents, or Music to see and delete individual large items.

Track down "System Data"#

Nearly every Mac shows a large, mysterious System Data category (it was called "Other" on older versions). Much of it is caches, logs, and old iOS backups. You can safely clear application caches in ~/Library/Caches, and old device backups pile up in ~/Library/Application Support/MobileSync/Backup. When you delete an app, drag it from the Applications folder to the Trash, but know it often leaves support files behind in ~/Library — a free tool like AppCleaner removes those leftovers with it.

Move big files off the drive — properly#

Some files are worth keeping but too big to sit locally: 4K home videos, RAW photo libraries, project archives. Move them rather than delete them.

Cloud storage keeps files online and off your drive. The catch is the free tier — here is what each service gives you at no cost:

• Google Drive — 15 GB (shared with Gmail and Google Photos)
• iCloud Drive — 5 GB
• Microsoft OneDrive — 5 GB
• Dropbox — 2 GB

OneDrive's "Files On-Demand" and iCloud's "Optimize Mac Storage" are the useful trick: files show up in your folders but only download when you open them, so they count toward the cloud, not your disk.

An external drive is better for large collections and for anything irreplaceable. A portable USB 3.0 (or USB-C) SSD or hard drive holds 1-4 TB for a modest price. Format it exFAT if you need it to work on both Windows and Mac. Before deleting the originals, open a few of the moved files from their new location to confirm they copied correctly — a two-minute check that prevents a permanent loss.

The mistakes that waste your afternoon#

• Deleting files but never emptying the bin. Deleted files sit in the Recycle Bin (Windows) or Trash (macOS) and still occupy the space until you empty it. This is why people delete for an hour and see zero change. Empty the bin as your final step.
• Manually deleting system folders. Never hand-delete Windows' WinSxS folder or System32, or macOS's /System. To trim the Windows component store safely, run Dism /Online /Cleanup-Image /StartComponentCleanup in an admin terminal instead.
• Trusting "one-click cleaner" apps that promise gigabytes. Registry cleaners in particular offer little real benefit and can break things; your built-in tools do the safe work.
• Treating cloud sync as a backup. If a folder syncs both ways, deleting the local copy deletes the cloud copy too. For true safety, keep a second, separate copy.

FAQ#

How much free space should I keep on my drive?#

Aim to keep at least 10-15% of an SSD free — for a 512 GB drive that is roughly 50-75 GB. Below that threshold, write speeds and overall responsiveness drop, and Windows or macOS updates may fail for lack of working room.

Is it safe to delete temporary files?#

Yes. Temporary files in Windows (%temp%) or macOS caches are created by apps for short-term use and are meant to be disposable. The system regenerates anything it still needs, so clearing them via Disk Cleanup or Storage settings carries no risk to your documents.

Why didn't my free space change after deleting a bunch of files?#

Almost always because the files are still in the Recycle Bin or Trash, which counts as used space until emptied. Empty it, and the space is reclaimed instantly. On macOS, also check whether Optimize Storage is keeping downloaded copies of iCloud files.

Does clearing space actually make my computer faster?#

On an SSD that was nearly full, yes — freeing space back above roughly 15% restores the controller's room to manage writes, which noticeably improves speed. On a mostly empty drive it will not, and it never adds RAM or a faster processor, so it fixes storage-related slowdowns, not every kind.