What Is Cached Data? Should You Keep It or Clear It?

Ever notice how a website or app feels way faster the second time you open it?
That speed boost is the result of cached data. It's like your device’s short-term memory, temporarily storing bits and pieces of what you've already seen, such as images, scripts, and layouts.

This background process saves time, cuts down on bandwidth, and helps everything feel smoother. But for something so common, it’s surprisingly misunderstood. A lot of people aren’t quite sure what cached data is, whether it’s safe to delete, or how much of it is quietly piling up behind the scenes.

Caching is the broader process that enables this. Whether you're using a phone, tablet, Solid-State Drives (SSD)-powered laptop, or even a basic hard drive, your device relies on caching to make repeated tasks faster. Operating systems (OS) also use it to optimize memory usage by keeping frequently accessed data in faster-access areas.

Still, cache isn’t permanent or perfect. It can become outdated, corrupted, or take up more space than you’d like. So the big questions remain: Should you clear it, and if so, when? Let’s break it all down. 

How does cached data work?

Before we talk about clearing your cache, let’s unpack what it’s actually doing behind the scenes. The process looks something like this:

• First-time visits trigger downloads of static content (HTML, CSS, images).
• These files are saved in memory or storage, depending on your device and app.
• Repeat visits reuse those stored files instead of reloading them from the internet.
• The result: faster load times, less data usage, and smoother navigation.

For cached data to be stored for re-access, there needs to be enough memory or storage space on your device. On a more technical side, the cache is very high up in the hierarchy of computer memory. Here’s a visual of this hierarchy for reference:

You can see just below the CPU register – the small building blocks of the computer processor – are a few levels of cache memory.

• L1, or level 1, is the primary level of cache built into the microprocessing chip.
• L2 and L3, or level 2 and 3, are the secondary cache level, which feeds the L1. It is slower than L1 by nanoseconds.

Cache memory has extremely low latency, meaning it can be accessed very quickly. You can test this by opening a new app or visiting a website you’ve never been to before, then revisiting it and comparing the speeds. Your second time around should be noticeably faster.

The flip side to low latency means not much memory can be stored. This is why small-sized files like web text and images are stored in the cache. However, it's important to note that corrupted cache files can lead to errors. In such cases, clearing the cache can resolve these issues.

What are the different types of cache?

Not all cached data lives in the same place, or serves the same purpose. From the files your browser saves to speed up web pages, to the microseconds shaved off by your device’s processor cache, each type plays a different role in making your digital experience faster and more seamless.

Here’s a breakdown of the most common types of cache and what they actually do:

• CPU cache: Built into your processor, this is the fastest type of cache. It stores instructions and data your system uses constantly, helping apps run smoothly and reducing lag at the microsecond level.
• Disk cache: This cache uses your device’s RAM to temporarily store files you’ve recently opened or saved. It reduces slow hard drive access and speeds up repeated file use.
• Web cache: Found in browsers, proxy servers, or CDNs, web cache stores web content like images and pages to speed up site loading and save bandwidth.
• App cache: Apps like Spotify, YouTube, or Instagram cache media files, previews, and session data to load faster and reduce buffering or reloads.
• System cache: Managed by your operating system, this cache helps speed up common system tasks, like keyboard popups, app switching, and screen transitions.
• DNS cache: Saves recently resolved domain names (like g2.com → IP address), reducing the time it takes to load familiar sites. Flushing it can fix loading issues.

Is cached data important?

You don’t need cached data to use your device, but without it, everything would feel slower, clunkier, and more repetitive. Cached data quietly improves performance in the background, helping things run faster, smoother, and more efficiently.

Cache memory also saves states. For example, if I close my X app and reopen it 10 minutes later, I’ll be able to scroll down and see posts that were previously loaded. Without cache, everything would need to reload. You can specifically remove the cache on certain websites but leave others in place, which can be particularly useful if you are managing multiple sites.

Additionally, caching is a key ingredient of economical large-scale cloud hosting, being vital for fallbacks such as CDNs (content delivery networks).

Cache vs. cookies: What’s the difference?

It’s easy to confuse cache with cookies. They’re both stored by your browser and take up space, but they serve very different functions behind the scenes.

Here’s how they compare:

When should you clear each?

• Clear your cache if a site isn’t loading right, looks outdated, or won’t display new changes.
• Clear your cookies if you’re having trouble logging in, seeing the wrong account, or want to reset a site's preferences.

Should I clear my cache?

So, if cached data isn’t that important, is it safe to erase? Well, that depends.

If you find your mobile device memory being drained by cached data, you should probably clear it. After all, cached data isn’t vital to an app or website's performance; it just means the files on it will have to be reloaded.

Although, constantly clearing your cache isn’t a permanent solution since you’ll eventually be reopening apps and revisiting websites at some point. The data will be re-cached, and the cycle will continue.

If you’re that strapped for memory, consider deleting old text messages, images, or video files on your device. It’s also worth looking into cloud-based file storage and sharing software like Google Drive or Dropbox if you want to hold on to your files. These options typically offer a free amount of cloud space.

How do I clear cached data on my devices?

If you’re all-in on clearing your cache, here’s how to do so on different operating systems:

How do I clear cache on an iPhone?

Follow these simple steps to clear the cache on iOS devices:

• Go to Settings > General > iPhone Storage.

• From here, you have a few options. Your first option is to clear the entire cache of apps you hardly or never use. This is under the recommendation “Offload Unused Apps.” The term offload is just iOS’ fancy phrase for clearing the cache.

• The second option is to scroll down and tap on individual apps with lots of cached data on your device. How can you tell this? Apple will list these apps from the highest usage of memory to the lowest.
• Simply offload the individual app to free up some temporary space on your device.

How do I clear cached data on Android? 

You can clear the cache on Android devices in the following ways.

Clear cache in Chrome app

• Open the Google Chrome app on your Android phone or tablet.
• Tap More on the three dots on the top right corner of the web page. 
• Tap History and then tap Clear browsing data and choose a time range at the top.
• Select a time range and check the boxes next to “Cached image files.”
• Tap Clear data to free up the browser cache on Chrome. 

Clear app cache

Let's take the Samsung Galaxy Note 8 as an example to understand how to clear the app cache from Android devices.

• Open the Settings menu on your Android phone and select Apps from the list
• Depending on your Android version, you might get an option to open installed apps, all apps, enabled, disabled, and other apps. Select all if using a Samsung Galaxy Note 8.
• Choose the appropriate option and navigate to the app whose cache you need to clear
• Select the app and tap Storage from the list of options inside the app data
• Tap Clear cache to free up space on your device

Clear cache on Firefox

It's quite easy to clear the Firefox cache. Follow these five steps:

• Select options by clicking Menu on the Firefox page.
• Tap the Privacy & Security panel.
• Click Clear Data in the Cookies and Site Data tab.
• Delete check marks in front of all other options and check Cached Web Content.

Frequently asked questions about cached data

Got more questions? We have the answers.

Q1. Can I clear the cache for just one app or website?

Yes. On most Android devices, you can go to Settings > Apps, choose a specific app, and clear its cache without affecting others. In browsers like Chrome or Firefox, you can clear site-specific data through the settings or privacy menu, which is helpful if one site is acting up while others work fine.

Q2. Does incognito mode use cached data?

Not exactly. Incognito mode doesn’t save new cached data after your session ends, but it may still use existing cache during that session to speed things up. Once you close the window, anything temporarily stored is wiped, so future visits won’t benefit from previous caching.

Q3. Will clearing the cache log me out of websites?

Not usually. Logins are typically stored in cookies, not cache. However, if you clear both cache and cookies at the same time, some sites may require you to sign in again.

Q4. How often should I clear my cache?

There’s no set schedule; it’s more of an “as-needed” task. Clear it when apps get glitchy, a site won’t load properly, or your storage is maxing out.

Q5. Will clearing cache make my device faster?

Sometimes, yes, especially if cached files are corrupted or bloated. But for long-term speed, it’s better to manage storage overall and keep apps updated.

Q6. What is a cache hit vs a cache miss?

A cache hit means your device found the file or data it needed in the cache, so it loaded quickly. A cache miss means that data wasn’t saved yet, so the device had to retrieve it from the original source, usually slower, but necessary to build the cache for next time.

Cache me if you can

Cache is great until it isn’t. While it’s meant to speed up digital life, it can silently accumulate, cause performance issues, or unexpectedly display outdated content.

That doesn’t mean you should nuke it on a schedule. Think of clearing your cache as a quick fix for occasional slowdowns, not a maintenance ritual. When a site won’t load properly, an app crashes, or your phone is pushing storage limits, it’s worth the tap.

For more lasting solutions, offloading unused apps or storing files in a cloud storage platform will have a much bigger impact. And if you run a website, configuring a CDN does for users what cache does for devices at scale.

Cache cleared? Great. Now let’s talk long-term storage. Explore top-rated Dropbox alternatives to keep your files backed up and your device clutter-free.

This article was originally published in 2019. It has been updated with new information.