What cache is and why you might want to clear it

Cache is temporary data your Mac stores to make programs run faster. When you visit a website, your browser saves images, scripts, and page layouts so it doesn't have to read them again. When you use an app, it stores settings and recent files. This speeds things up — but over time, cache can take up disk space, cause programs to behave oddly, or show you outdated information.

You don't need to clear cache regularly. Most people clear it only when a website looks broken, an app is acting slow, or they want to free up storage space. Clearing cache won't hurt your Mac — the data will rebuild as you use your programs again.

Key Takeaways

  • Cache is temporary data stored by your browser and apps to load faster, and clearing it frees up disk space without damaging your system.
  • Safari, Chrome, and Firefox each have their own cache location and clearing method, found in their settings or preferences menu.
  • You can clear cache for a specific time period (last hour, last day, all time) rather than deleting everything at once.
  • System cache stored by macOS itself can be cleared by restarting your Mac or using Disk Utility, but this is rarely necessary.
  • If a website looks broken or an app won't update, clearing cache is often the first troubleshooting step to try.

Clearing cache in Safari

Safari is the default browser on Mac. To clear its cache, open Safari and click Safari in the menu bar at the top of the screen. Select Settings (or Preferences on older Macs). Click the Privacy tab.

You'll see a button that says Manage Website Data. Click it to see all the websites that have stored data on your Mac. You can select individual sites and click Remove, or click Remove All to clear everything at once. Close the window when you're done.

If you want to clear cache automatically every time you close Safari, go back to the Privacy tab and check the box next to Remove all website data when quitting Safari. This is useful if you don't want Safari remembering which sites you visit.

Clearing cache in Chrome and Firefox

In Chrome, click the three vertical dots in the top right corner and select Settings. Click Privacy and security on the left side, then Clear browsing data. A window will open. Make sure Cached images and files is checked. At the top, choose your time range — All time will clear everything, or pick Last hour, Last day, or Last 4 weeks if you only want to clear recent cache. Click Clear data.

In Firefox, click the three horizontal lines in the top right and select Settings. Click Privacy & Security on the left. Under Cookies and Site Data, click Clear Data. Make sure Cached Web Content is checked and click Clear.

Both browsers let you set them to clear cache automatically when you close the program. In Chrome, check Clear cookies and site data when you quit Chrome under Privacy and security. In Firefox, set Delete cookies and site data when Firefox is closed under Cookies and Site Data.

Clearing system cache on your Mac

Your Mac itself stores cache files separate from your browser. These live in hidden folders and rarely cause problems, but you can clear them if your Mac is running slowly or you need disk space. The simplest way is to restart your Mac — this clears temporary files from memory.

For a deeper clean, open Finder and press Command + Shift + G to open the "Go to Folder" dialog. Type ~/Library/Caches and press Enter. This shows cache folders for your apps. You can delete individual app caches by dragging them to the Trash, but be careful not to delete cache for apps you're currently using. Empty the Trash when you're done.

If you're not comfortable deleting files manually, Disk Utility can help. Open Disk Utility (search for it in Spotlight), select your Mac's hard drive on the left, and click First Aid. This checks your disk and clears some temporary files, though it won't delete as much as manual clearing.

How much space cache actually takes up

Browser cache is usually small — typically between 100 MB and 1 GB per browser unless you've been using it for years without clearing. System cache varies widely depending on how many apps you use and how long your Mac has been running. If your Mac has a 256 GB drive and you're running low on space, clearing cache might free up a few gigabytes, but it won't solve a serious storage problem.

If you're trying to free up significant space, look first at large files in your Downloads folder, old backups, or duplicate photos. Cache is worth clearing as part of general maintenance, but it's rarely the main culprit when a Mac runs out of room.

When to clear cache and when not to

Clear cache when a website displays incorrectly, an app won't update to the latest version, or you're troubleshooting a program that's behaving strangely. Clearing cache is also useful if you're concerned about privacy — it removes data about which sites you've visited and what you've searched for.

Don't clear cache if you're trying to speed up your Mac in general. Cache actually helps performance by storing data locally, so clearing it might make things slower at first as programs rebuild their cache. If your Mac is slow, the problem is usually something else — too many apps running at once, a full hard drive, or an older processor.

Frequently Asked Questions

Will clearing cache delete my passwords or saved information?

No. Cache and cookies are different. Cache stores images and page layouts. Cookies store login information and preferences. When you clear cache, you can choose whether to also clear cookies — they're separate checkboxes in most browsers. If you uncheck cookies, your passwords and saved logins stay.

Why does a website still look broken after I clear cache?

The website itself might be down or having problems on the server side, which clearing your cache won't fix. Try the site in a different browser to see if the problem is specific to one browser. If it looks fine in another browser, the issue is with your first browser's cache or settings, not the website.

How often should I clear cache?

Most people don't need to clear cache on a schedule. Clear it when you notice a problem, when you're low on disk space, or if you're concerned about privacy. If you want to clear it regularly, set your browser to clear cache automatically when you close it — this is a good middle ground.

Does clearing cache slow down my Mac?

Clearing cache might make your Mac slightly slower for a few minutes after you do it, because programs have to rebuild their cache. But this is temporary. If your Mac feels slow in general, clearing cache won't fix it — the problem is usually something else like too many background apps or a full hard drive.

Can I clear cache for just one website instead of all of them?

Yes. In Safari, click Manage Website Data in Privacy settings and select the site you want to remove. In Chrome and Firefox, you can select individual sites before clearing, though both browsers make it easier to clear all at once. If you only want to clear one site's cache regularly, consider using your browser's private browsing mode for that site instead.