What Does "Clear Your Cache" Actually Do?

"Have you tried clearing your cache?" is the "have you tried turning it off and on again" of the web. It does fix things, but most people don't know what it actually deletes, and plenty clear far more than they mean to. Here's what the cache is, what clearing it does and doesn't do, and the faster fix you should try first.

Steven clears everything, signs himself out of forty sites, then spends an evening resetting passwords. For a page that just needed one refresh. — Nyx

What the cache actually is

When you visit a site, your browser saves copies of the heavy parts: images, fonts, layout files and scripts. Next time you visit, it reuses those copies instead of downloading them again. That's the cache, and it's why sites load faster the second time.

The problem: when a website updates, your browser can keep using its old saved copy. Old layout file plus new page equals a site that looks broken, with buttons in the wrong place or a page that never finishes loading.

The cache is not the same as these, which sit next to it in the same menu:

• Cookies and site data: small notes sites leave so they remember you. This is what keeps you signed in and remembers your settings. Delete these and you get signed out.
• Browsing history: the list of pages you visited.
• Saved passwords: kept separately. A normal "clear cache" doesn't touch them, but the bigger "clear everything" options can, so read the boxes.

Try this first: a hard refresh

If one page looks wrong, you usually don't need to clear anything. A hard refresh reloads just that page and fetches fresh copies of its files:

• Windows (Chrome, Edge, Firefox): Ctrl + Shift + R or Ctrl + F5
• Mac (Chrome, Firefox): Cmd + Shift + R

Nothing else gets deleted, and you stay signed in. This fixes the "site looks broken after an update" problem most of the time.

If that doesn't work: clear the cache only

On a computer, the shortcut Ctrl + Shift + Delete (Cmd + Shift + Delete on a Mac) opens the "clear browsing data" window in Chrome, Edge and Firefox.

• Pick a time range. "Last hour" or "Last 24 hours" is often enough.
• Tick only "Cached images and files" (Firefox calls it "Temporary cached files and pages").
• Untick cookies unless you actually want to be signed out everywhere.
• Clear, then reload the page.

On a phone:

• Chrome on Android: tap the three dots → Delete browsing data, then tick only cached images and files.
• Safari on iPhone: Settings → Safari (on newer iOS, Settings → Apps → Safari) → Clear History and Website Data. Note that Safari clears history, cookies and cache together here, so you will be signed out of sites.

Only one site misbehaving? Most browsers let you clear data for just that site: click the small icon to the left of the web address and look for site data or cookies. That fixes the one site without touching anything else.

What clearing the cache does NOT do

• It doesn't make you anonymous. Websites, your internet provider and your network can still see what you visit. It only removes copies stored on your device.
• It doesn't remove viruses or malware. If you think your device is infected, that's a job for proper security software, not a browser setting.
• It doesn't speed your computer up. Sites will actually load a little slower right afterwards, because the browser has to download everything again.
• It doesn't need doing regularly. Browsers manage the cache themselves. Clear it when something's wrong, not as a weekly ritual.

The privacy part

The cache, history and cookies together show which sites a device has visited, to anyone who uses that device. If you share a computer, that's the real reason to clear them. Easier still: use a private window (Incognito in Chrome, InPrivate in Edge). It keeps its own cache and cookies and throws them away when you close the window. It doesn't hide you from the websites or your network, just from the next person at the keyboard.

The one-minute version

• The cache is saved copies of website files so pages load faster.
• One page looks broken? Hard refresh first: Ctrl + Shift + R (Cmd + Shift + R on a Mac).
• Still broken? Clear cached images and files only and leave cookies ticked off.
• Clearing cookies is what signs you out. Clearing the cache doesn't.
• It isn't a privacy cloak, a virus scan or a speed boost.

Want to see what the browser is actually doing when it loads a page? What happens when you type a URL walks through it. And if a "your browser is infected, clear it now" pop-up ever tells you to call a number, that's a scam; see is this link safe?

Hard refresh first. Nuclear option last. Steven, write that on a sticky note. — Nyx

Now you know what each box in that menu does, which is more than most people who tell you to clear it. — Nova