Yes, you can delete most temporary files without breaking anything
Temporary files are scraps left behind by programs while they run — partial downloads, cache copies, work-in-progress versions. Your operating system and applications create thousands of them. Most are safe to delete once the program closes, and deleting them frees up disk space without affecting how your computer works.
The catch is that some temporary files are still in use, and deleting those while a program is running can cause crashes or data loss. The safest approach is to delete temp files when nothing is actively using them — typically during a restart or after closing all open programs.
Key Takeaways
- Temporary files accumulate in specific folders on your hard drive and are almost always safe to delete once programs close.
- Windows stores temp files in C:\Users\[YourUsername]\AppData\Local\Temp and C:\Windows\Temp; macOS stores them in /var/tmp and /private/tmp.
- The safest time to delete temp files is after restarting your computer or when no programs are running.
- Using built-in tools like Disk Cleanup (Windows) or Storage Management (macOS) is safer than manually deleting from temp folders.
- System files and cache files serve different purposes — cache speeds up programs, while temp files are genuinely temporary waste.
Where temporary files live on your computer
On Windows, temporary files collect in two main locations. The user temp folder is at C:\Users\[YourUsername]\AppData\Local\Temp, where individual programs store their working files. The system temp folder is at C:\Windows\Temp, where Windows itself creates temporary files during updates and system operations.
On macOS, temporary files go into /var/tmp (for files that persist across restarts) and /private/tmp (for files deleted on restart). Both folders are hidden by default, so you won't see them in Finder unless you enable viewing hidden files.
You can navigate to these folders manually, but most people never need to — the files are out of sight and take up relatively little space unless your computer has been running for months without a restart.
What happens when you delete temp files while programs are running
A program that is actively using a temporary file may crash if that file disappears. This is rare with modern operating systems, which lock files in use, but it can happen. A program might be writing to a temp file, pause, and then try to read from it — if you delete it during that pause, the program loses data or stops responding.
The risk is lowest with files that programs created hours or days ago. The risk is highest with files created in the last few minutes or files from programs you have open right now. This is why restarting before you delete is the safest move: it closes all programs and releases all file locks.
The safest ways to delete temporary files
On Windows: Use Disk Cleanup, the built-in tool designed for this task. Press the Windows key, type "Disk Cleanup", and open it. Select your C: drive, then check the boxes next to "Temporary files" and "Temporary internet files". Click Delete. Disk Cleanup knows which files are truly safe to remove and won't touch anything a running program needs.
Alternatively, restart your computer, then open File Explorer and navigate to C:\Users\[YourUsername]\AppData\Local\Temp. Select all files (Ctrl+A), then delete them. After a restart, any files still there are orphaned and safe to remove. Do the same for C:\Windows\Temp if you want to be thorough.
On macOS: Open System Settings, go to General, then Storage. Click Manage next to your storage bar. macOS will show you cache and temporary files and offer to remove them. This is the easiest route. Alternatively, restart your Mac, open Finder, press Cmd+Shift+G to open "Go to Folder", type /var/tmp, and delete the contents. Repeat for /private/tmp.
The difference between temp files and cache files
Temporary files are work-in-progress scraps that programs discard when they close. Cache files are copies of data that programs keep around to run faster next time — your web browser caches images and web pages so they load quicker on your next visit.
Both are safe to delete, but they serve different purposes. Deleting cache files means programs will run slightly slower the next time you use them because they have to rebuild the cache. Deleting temp files has no effect on performance — they were going to be deleted anyway.
If you are running low on disk space, deleting both is fine. If you are just cleaning up, temp files are the priority because they are pure waste. Cache files are optional.
When you should not delete temporary files
Do not delete temp files from a program that is currently open. If you have a large file open in an editor, that program may be using a temporary file to store changes before you save. Deleting it could cause you to lose work.
Do not delete temp files while Windows Update or macOS is installing updates. The operating system uses temporary files during the update process, and deleting them mid-update can corrupt the installation.
Do not delete temp files if your computer is running slowly at that exact moment. A slow computer often means a program is actively writing to disk. Wait for the slowness to pass, restart, and then delete.
How often you should delete temporary files
There is no fixed schedule. Temporary files are small individually, and most operating systems clean them up automatically on restart. If your hard drive has plenty of free space — more than 10 percent of its total capacity — you can ignore temp files entirely.
If you are running low on space or your computer has been on for weeks without a restart, deleting temp files is a quick way to reclaim a few gigabytes. Run Disk Cleanup or Storage Management once every few months, or whenever you notice your drive is getting full.
Frequently Asked Questions
Will deleting temp files make my computer faster?
No. Temporary files do not slow down your computer while they sit on disk. Deleting them frees up storage space, which can help if your drive is nearly full, but it will not improve speed or performance. If your computer is slow, the problem is usually something else — too many programs running at startup, a full hard drive, or a program using a lot of memory.
Can I delete temp files while my computer is on?
Yes, as long as you use Disk Cleanup or Storage Management rather than manually deleting from the temp folders. These tools know which files are safe to remove while the system is running. Manual deletion is riskier because you might remove a file a program is actively using.
What if I delete a temp file and a program crashes?
Restart your computer. The program will recreate the temp file it needs the next time it runs. If the crash caused data loss in an open document, you may not be able to recover it, which is why restarting before deleting is the safest approach.
Do I need to empty the recycle bin after deleting temp files?
No. Emptying the recycle bin is optional and does not affect your computer's performance. If you want to permanently delete the files and free up the space they occupy in the recycle bin, you can empty it, but it is not necessary.
Are temporary internet files the same as temp files?
No. Temporary internet files are cached web pages and images stored by your browser. Temp files are work-in-progress scraps from all programs. Both are safe to delete, but they are stored in different locations and serve different purposes. Disk Cleanup lets you delete both at once.