Check storage use on Windows with built-in tools

Windows has a built-in storage analyzer that shows you exactly which folders and programs are taking up space. Open Settings, go to System > Storage, and you'll see a breakdown by category — apps, documents, photos, videos, and other files. Click on any category to drill down further and see individual items.

For a more detailed view of which folders are largest, use the Disk Usage Analyzer. Right-click on your C: drive (or whichever drive you want to check), select Properties, then click "Disk Cleanup". This shows temporary files you can safely delete. For a visual map of your entire drive, download WizTree or TreeSize Free — both are free programs that display folders as rectangles sized by how much space they use, making it easy to spot the culprits at a glance.

Check storage use on Mac with Activity Monitor and Finder

On Mac, the easiest method is Finder's built-in tool. Open Finder, click on your drive in the sidebar, then go to File > Get Info. This shows total capacity and available space. To see what's taking up room, use the Storage Management tool: click the Apple menu, select About This Mac, then click Storage. You'll see a colored bar showing how much space each category uses — Applications, Documents, Photos, Backups, and Other.

Click on any category to see what's inside. If "Other" is large, that often means cache files, temporary downloads, or old backups. For a detailed folder-by-folder breakdown, download Disk Diag or OmniDiskSweeper — both are free and show you exactly which folders are largest. Activity Monitor can also show you which running programs are using the most memory, though that's different from storage space.

Key Takeaways

  • Windows Settings > System > Storage shows what's using space by category, and you can click into each one to see individual files and folders.
  • Mac's Storage Management tool (Apple menu > About This Mac > Storage) displays a color-coded breakdown of what's taking up room on your drive.
  • Free programs like WizTree on Windows or OmniDiskSweeper on Mac show you a visual map of your entire drive so you can spot large folders instantly.
  • Temporary files, old backups, and cached data often take up more space than you realize, and built-in cleanup tools can remove them safely.
  • Check storage use regularly — waiting until your drive is nearly full can slow down your computer and make it harder to install updates.

Understand what the different storage categories mean

When you look at storage breakdowns, you'll see categories like Applications, Documents, Photos, Videos, and Other. Applications are programs you've installed. Documents includes word files, spreadsheets, PDFs, and anything you've saved to your Documents folder. Photos and Videos are self-explanatory, though they often take up far more space than people expect — a single 4K video can be several gigabytes.

The "Other" category is the catch-all for everything else: temporary files, cache data, browser downloads, old backups, and system files. This category often grows without you noticing because it's not a single folder you can see. On Windows, temporary files live in AppData and Temp folders. On Mac, they're scattered in Library folders. Both operating systems create cache files to speed up programs, but these can accumulate over time.

Find large individual files you might have forgotten about

Sometimes a single file or two is taking up most of your space. Video files, disk images, and old backups can each be several gigabytes. To find these, use your file explorer's search function. On Windows, open File Explorer, right-click on your drive, and select Search. You can filter by file size — search for files larger than 1 GB to see what's hogging space. On Mac, open Finder, click on your drive, then use the search box at the top right and set the file size filter to show only large files.

Look for old video projects, downloaded installers you no longer need, and backup files with names like "backup.zip" or "archive.dmg". These are often safe to delete once you've confirmed you don't need them. Before deleting anything large, move it to an external drive first if you think you might want it later.

Check what programs are using the most space

Some programs install large support files or create data folders that grow over time. On Windows, go to Settings > Apps > Apps & Features, and you'll see the size of each installed program. Click on any program to see options to uninstall or repair it. Programs like Adobe Creative Suite, games, and video editing software often take up 5 to 20 gigabytes each.

On Mac, open Applications folder in Finder and right-click on any program to select Get Info, which shows its size. Keep in mind this shows only the program itself, not the data files it creates — those are usually stored in your Documents or Library folders. If a program you rarely use is taking up significant space, you can uninstall it by dragging it to the Trash, though some programs leave behind preference files and caches that you may want to clean up separately.

Clean up cache and temporary files safely

Cache files and temporary data are created by your operating system and programs to speed things up, but they can accumulate to gigabytes over time. On Windows, use the built-in Disk Cleanup tool: right-click your drive, select Properties, then click Disk Cleanup. Check the boxes for Temporary Files, Recycle Bin, and Temporary Internet Files, then click Delete. This is safe — these files are meant to be temporary.

On Mac, you can manually empty the Trash (right-click Trash in the dock and select Empty Trash), clear your browser cache (in Safari, go to History > Clear History, or in Chrome, go to Settings > Privacy > Clear Browsing Data), and delete old downloads from your Downloads folder. For a more thorough cleanup, free tools like CleanMyMac X or Disk Diag can remove old cache files, but be cautious with third-party cleaning tools — stick to well-reviewed ones and avoid anything that promises to "speed up" your computer dramatically, as these claims are often exaggerated.

Monitor storage over time to catch problems early

Storage problems usually don't appear overnight — they build up gradually as you download files, install programs, and create backups. Check your storage use once a month so you notice when something is growing unusually fast. If your "Other" category suddenly jumps by several gigabytes, it often means a program is creating large cache files or your system is storing old backups.

Keep your drive at least 10 to 15 percent free for your operating system to function smoothly. When you get close to full, your computer slows down, updates fail, and programs may crash. If you're consistently running low on space, consider moving old files to an external drive, deleting programs you no longer use, or upgrading to a larger drive if that's an option for your device.

Frequently Asked Questions

Is it safe to delete files from the "Other" category?

Some files in "Other" are safe to delete — temporary files, old downloads, and browser cache. Others, like system files and program data, should be left alone. Use the built-in cleanup tools (Disk Cleanup on Windows, or clearing cache in your browser on Mac) rather than manually deleting from system folders. If you're unsure about a specific file, search for its name online before deleting it.

Why is my backup taking up so much space?

Backups can be enormous because they copy everything on your drive, including programs, documents, and media. On Windows, old System Restore points and File History backups accumulate. On Mac, Time Machine backups can grow to match your entire drive size. You can delete old backups manually — on Windows, go to Settings > System > Storage > Temporary Files and look for old restore points; on Mac, open Time Machine preferences and delete old backups. Just keep at least one recent backup in case you need it.

What's the difference between storage space and memory?

Storage is the permanent space on your drive where files and programs live — deleting a file frees up storage. Memory (RAM) is temporary space your computer uses while programs are running — it clears automatically when you restart. When people say their computer is "slow," it's usually a storage problem (drive nearly full) or a memory problem (too many programs open), not the same thing. Check storage with the tools described above; check memory with Task Manager on Windows or Activity Monitor on Mac.

Can I move files to an external drive to free up space?

Yes, moving files to an external drive frees up space on your main drive. Connect the external drive, open your file explorer, and drag files or folders to the external drive. This works well for photos, videos, documents, and old projects. Don't move program files or system folders — programs need to stay on your main drive to work properly. After moving files, empty your Recycle Bin or Trash to complete the deletion.