Windows and Mac both have built-in tools to show you which files and folders are using the most disk space
Your PC slows down when the hard drive fills up, but you probably don't know which files are the culprits. Windows and Mac come with free tools that scan your entire drive and show you exactly what's eating space — no third-party software needed. On Windows, the built-in Storage Sense tool breaks down space by category and lets you drill down to individual folders. On Mac, the System Information window does the same thing. Both take a few minutes to scan and show you the real numbers, not estimates.
The advantage of using these built-in tools is that they're already on your computer and require no installation or setup. They also integrate directly with your operating system, so they can show you information that third-party tools sometimes miss. Once you know what's taking up space, you can make informed decisions about what to delete, uninstall, or move to external storage.
Key Takeaways
- Windows Storage Sense (Settings > System > Storage) shows what's using space by category and lets you see the largest folders on your drive.
- Mac System Information (Apple menu > About This Mac > Storage) displays a visual breakdown of what's taking up room and which apps are largest.
- Both tools scan your entire drive automatically, so you don't have to manually hunt through folders.
- Once you identify the space hogs, you can delete old files, uninstall unused programs, or move large folders to external storage.
- Running these scans every few months helps you catch space problems before your drive gets critically full.
How to check disk space on Windows using Storage Sense
Open Settings by pressing Windows key + I, then go to System > Storage. You'll see a bar showing how much space is used and how much is free. Below that, Storage Sense breaks down space by category: Apps & features, Documents, Pictures, Videos, Music, and Other. Click on any category to see the largest items in that folder.
To dig deeper into a specific category, click on it. For example, if Videos is taking up 200 GB, click Videos and you'll see a list of your video files sorted by size. You can also click "Show all categories" at the bottom to see a complete breakdown. If you want to see which folders are largest across your entire drive, scroll down and look for "Largest items" — this shows individual files and folders ranked by size, which is the fastest way to find what to delete. Storage Sense also offers automatic cleanup options. You can turn on "Storage Sense" to automatically delete temporary files and items in your Recycle Bin after a certain number of days. This is optional but useful if you want Windows to handle cleanup without you having to remember.
How to check disk space on Mac using System Information
Click the Apple menu in the top-left corner, then select "About This Mac." Click the Storage tab. You'll see a colored bar showing how much space is used by different categories: Photos and Videos, Audio, Apps, Documents, System Data, and Other. The numbers appear both as a bar and as text, so you can see the exact gigabytes used by each type.
Unlike Windows, Mac's built-in tool doesn't let you click into categories to see individual files. If you need more detail, you can use Finder to manually browse folders. Open Finder, click on your hard drive in the sidebar, then use View > as List to sort folders by size. Right-click on a folder and select "Get Info" to see exactly how much space it's using. This is slower than the automatic scan, but it works if you want to investigate a specific folder. Mac also has a "Manage" button in the Storage tab that shows recommendations for optimizing space — things like deleting old downloads, emptying the trash, or storing photos in iCloud instead of locally. These are suggestions, not automatic actions, so you stay in control.
Understanding the "Other" category and what it contains
Both Windows and Mac show an "Other" category that often takes up surprising amounts of space. This includes temporary files, cache files, system logs, and miscellaneous data that doesn't fit neatly into Apps, Documents, or Media. On Windows, "Other" can include old Windows installation files, temporary internet files, and leftover data from uninstalled programs. On Mac, it includes similar items plus things like language files for apps you don't use.
You can safely delete some of this, but not all. Temporary files and cache are safe to remove — your system will recreate them as needed. Old Windows installation files (usually in a folder called Windows.old) can be deleted if you're sure your current Windows installation is working properly. However, system files themselves should never be deleted. If you're unsure whether something is safe to remove, leave it alone or search online for the specific filename before deleting. When in doubt, it's better to keep a file than to accidentally remove something your system needs to run.
Finding and removing large files you no longer need
Once you've identified what's taking up space, the next step is deciding what to delete. Start with the obvious candidates: old video files, downloaded installers you no longer need, duplicate photos, and archived project folders. Both Windows and Mac let you sort by file size, which makes it straightforward to target the biggest space wasters first.
On Windows, open File Explorer, navigate to the folder you want to clean, click View, and select "Details." Click the "Size" column header to sort by size — largest files appear at the top. On Mac, open Finder, navigate to the folder, click View > as List, then click the "Size" column to sort. You can also use the search function to find files by date — for example, search for files modified more than a year ago, which are often safe to delete. Before deleting anything large, consider moving it to external storage instead. A USB drive or external hard drive costs $30 to $100 and gives you a backup copy while freeing up space on your main drive. This is especially useful for old photos, videos, and archived work files you want to keep but don't need quick access to.
When to uninstall programs instead of deleting files
If your Apps category is taking up significant space, uninstalling unused programs is often faster than hunting for individual files. Both Windows and Mac show you how much space each app uses, so you can target the biggest ones first. On Windows, go to Settings > Apps > Apps & features, click on an app, and select Uninstall. On Mac, open Applications folder in Finder, right-click an app, and select Move to Trash.
Be selective — only uninstall programs you genuinely don't use. Uninstalling something you use occasionally is not worth the hassle of reinstalling it later. However, if you have multiple versions of the same program (like old versions of Adobe Creative Suite or Microsoft Office), you can safely remove the older ones. Also check for bloatware — programs that came pre-installed on your PC that you've never opened. These are prime candidates for removal. One warning: uninstalling a program removes the process itself, but it may leave behind configuration files and data. On Windows, these leftover files are usually small, but on Mac they can add up. If you want a completely clean removal, you can manually delete the app's folder in Library > process Support, but only do this if you're certain you won't need the program again.
Setting up regular checks to prevent your drive from filling up
Disk space problems don't happen overnight — they creep up gradually as you read files, install programs, and accumulate photos and videos. The best way to avoid running out of space is to check your disk usage every few months. Set a calendar reminder to open Storage Sense or System Information quarterly and see what's changed.
You can also enable automatic cleanup features. On Windows, Storage Sense can automatically delete temporary files and Recycle Bin contents after 30 days. On Mac, you can enable iCloud Photo Library to store photos in the cloud instead of locally, which frees up gigabytes of space. Neither of these is mandatory, but both reduce the amount of manual cleanup you'll need to do. If you regularly work with large files — video editing, photo libraries, or game installations — consider upgrading to a larger drive or adding external storage as a permanent part of your setup. A 1 TB or 2 TB external drive is inexpensive and gives you room to grow without constantly deleting files.
Frequently Asked Questions
Is it safe to delete files from the "Other" category?
Some files in "Other" are safe to delete — temporary files, cache, and old downloads. However, system files should never be deleted. If you're unsure about a specific file, search for its name online before deleting. When in doubt, it's better to keep a file than to accidentally remove something your system needs to run.
Why does my drive show as full when Storage Sense says I have free space?
This usually means Windows is counting reserved space or system files that aren't displayed in the breakdown. Restart your PC and run Storage Sense again — the numbers often update after a reboot. If the problem persists, your drive may actually be nearly full and you should delete files when ready.
Can I move my entire Documents or Pictures folder to external storage?
Yes. On Windows, right-click the folder, select Properties > Location, and choose a new drive. On Mac, you can move folders manually by dragging them to external storage, but this breaks some system integrations — it's better to use iCloud or a backup service instead. For large media libraries, external storage is the simplest solution.
What's the difference between deleting a file and emptying the Recycle Bin?
When you delete a file, it goes to the Recycle Bin (Windows) or Trash (Mac) but still takes up space. You must empty the Recycle Bin or Trash to actually free up that space. Storage Sense can automate this, or you can right-click the Recycle Bin and select "Empty Recycle Bin" manually.
Should I use a third-party disk cleanup tool?
No. Windows Storage Sense and Mac System Information do everything you need for free. Third-party tools often promise faster cleanup but can delete important files or slow down your system. Stick with the built-in tools.