What are temporary files, and is it safe to delete them?
Working files that programs meant to tidy up and did not. Which categories are genuinely safe to clear, which cost you something, and why the system already does most of it.
- Difficulty
- beginner
- Time
- 20 min
- Read
- 3 min
- Safety
- caution
Short answer
Yes, with the system's own tool. Temporary files are scratch files created during installations, updates, printing, browsing and editing, which should be deleted automatically and often are not. Windows' storage sense and disk clean-up, and macOS's storage management, remove the safe categories. Clearing browser cache and the update cache is fine; clearing downloads deletes real files; and removing the previous installation ends your ability to roll back an update.
Safety
Step by step
- Know what actually accumulates.Installer files kept after a program is installed. Update packages kept after they are applied. Browser caches holding copies of pages and images. Thumbnail and preview caches. Crash reports and logs. Print spool files. Application scratch files from editing large documents, photographs or video.
- Understand why they are still there.Programs are supposed to clean up after themselves and frequently do not, particularly if they crashed, were force-quit, or were uninstalled untidily. Nothing has gone wrong; it is ordinary accumulation.
- Use the system's tool, not a third-party cleaner.Windows offers storage sense, which does it on a schedule, and disk clean-up including a system files mode. macOS offers storage management with recommendations. Both know what is in use and what is not, which no external tool can determine as reliably.
- Judge the categories individually.Temporary and installer files: safe. Update cache: safe, and it will be re-downloaded if needed. Thumbnail cache: safe, rebuilt on demand, and folders will be briefly slower afterwards. Browser cache: safe, and pages reload more slowly for a while. Recycle bin: safe if you are sure. Downloads: not temporary — these are real files you chose to save.
- Take care with the two costly ones.Removing the previous installation reclaims a lot and forfeits the rollback. Reducing restore points or snapshots reclaims a lot and forfeits your ability to undo a change or recover an older version of a file. Both are legitimate choices to make deliberately.
- Do not delete from system folders by hand.Guides that tell you to empty a particular Windows temp folder or a Library subfolder are working from an obsolete idea. The safe subset of that folder is exactly what the clean-up tool removes, and the unsafe subset is what breaks programs.
- Set it to happen automatically.Windows' storage sense can clear temporary files and empty the recycle bin after a set period. Turn it on and stop thinking about it. macOS has similar automatic options in its storage recommendations.
- Expect modest results.On a machine that has not been cleaned in years, several gigabytes. On a well-behaved machine, very little. If you need tens of gigabytes, the answer is in large files and snapshots rather than temporary files.
Questions people ask
Will deleting temporary files speed up my computer?
No, except in the specific case where the drive was so full that the system had no working room. Space is not speed. The claim is the foundation of the cleaner industry and it does not hold.
Is it safe to clear my browser cache?
Yes. Pages will load a little more slowly the first time afterwards. It is a reasonable step if a site is misbehaving and it is not something to do weekly.
What about the folder simply called Temp?
It holds scratch files from programs, some of which are open right now. Let the clean-up tool handle it — it skips what is in use, and manual deletion does not.
Do temporary files contain personal data?
They can — cached pages, document previews and print spool files among them. That is a reason to clear them on a machine you are passing on, and one more reason to wipe a drive properly rather than deleting folders.