How to Clear Cache on iPhone - Every Method That Actually Works

Your iPhone says storage is full, so you searched for how to clear the cache. Reasonable - it is what you would do on a computer. Here is the honest version before you spend twenty minutes on it.

There is no single “clear cache” button on an iPhone, and there never has been. Safari has its own control. Every other app keeps its cache sealed inside its own sandbox, where neither you nor any other app can reach it. And when you have cleared everything that genuinely can be cleared, you will typically have recovered somewhere between 100 MB and 1.5 GB.

That is worth doing, and this guide covers every method that works. But if your phone is full by tens of gigabytes, the cache is not why, and the last section of this guide tells you where the space actually went.

What can and can’t be cleared

How to clear Safari cache on iPhone

This is the only true cache-clearing control iOS gives you, and it is the one worth doing first.

1. Open Settings
2. Tap Apps, then Safari (on iOS 17 and earlier, Safari is in the main Settings list, not under Apps)
3. Scroll down and tap Clear History and Website Data
4. Choose a time range - All history clears the most
5. Confirm

What this removes: your browsing history, cached page assets, and cookies for every site.

What it does not touch: bookmarks, saved passwords, AutoFill details, your Reading List, or downloaded files.

What it costs you: you will be signed out of every website you were logged into. Banking sites, webmail, anything with a “remember this device” flag - all of it will ask you to log in again, and sites using two-factor authentication may treat your phone as a new device.

If that trade is not worth it, use the targeted method below instead.

How to clear cookies on iPhone without clearing history

Safari lets you remove cookies and cached data per site, leaving your history alone.

1. Settings → Apps → Safari
2. Scroll to the bottom and tap Advanced
3. Tap Website Data

You will see every site holding data on your phone, largest first. Swipe left on any single entry to delete it, or tap Remove All Website Data to clear the lot while keeping your browsing history.

This is the better option when one site is misbehaving, or when you want the cookies gone but do not want to be logged out of everything at once. It is also the only place iOS shows you which sites are actually storing the most.

How to clear app cache on iPhone

Here is where most guides start inventing things, so plainly:

iOS has no universal app cache clear. There is no Settings screen that empties every app’s cache, and no third-party app can do it either. This is not an oversight - it is the sandbox. Every app on your iPhone runs inside a container that no other app and no global settings toggle is permitted to open. It is the same design that stops a flashlight app reading your banking app’s session tokens.

That leaves you three real options.

Option 1: the app’s own settings

Some apps ship their own cache control. It varies, but the common ones:

• Chrome - three dots → Settings → Privacy and Security → Delete Browsing Data
• Spotify - Settings → Storage → Clear Cache (downloaded music can run to several GB)
• WhatsApp - Settings → Storage and Data → Manage Storage, which sorts chats by size and lets you delete large media in bulk
• Telegram - Settings → Data and Storage → Storage Usage
• YouTube, Instagram, TikTok - no cache control at all; offload them instead

It is worth checking the two or three apps at the top of your storage list rather than working through all of them.

Option 2: offload the app

This is Apple’s official answer, and it is genuinely good.

1. Settings → General → iPhone Storage
2. Wait for the list to build, then tap the app you want
3. Tap Offload App

Offloading deletes the app binary and its entire cache, while keeping every document and setting it stored. The icon stays on your Home Screen with a small cloud badge. Tap it and the app reinstalls and picks up exactly where you left off - your logins, drafts and preferences intact.

The Delete App button directly below it removes the data too. Read carefully before tapping: the two buttons sit next to each other and only one is reversible.

You can also turn on Offload Unused Apps in Settings → App Store, which does this automatically to anything you have not opened in a long time.

Option 3: delete and reinstall

For an app with no cache control that you are still signed into elsewhere, deleting and reinstalling clears everything. You will be logged out and any local-only data is gone, so this is a last resort rather than a routine.

Clear the Messages cache

Messages is quietly one of the biggest consumers on a well-used phone, because every photo, video, voice note and GIF anyone has ever sent you is still there.

Set an expiry date:

Settings → Apps → Messages → Keep Messages → 30 Days or 1 Year

iOS will ask whether to delete everything older than that now. On a phone that has been carried for a few years, this single change can free several gigabytes.

Or clear just the big attachments:

Settings → General → iPhone Storage → Messages → Review Large Attachments

This lists every attachment by size, largest first. You keep the conversations and delete only the 400 MB videos, which is usually the better trade.

Clear the Mail cache

Mail caches every attachment you have ever opened and offers no button to clear it. The workaround is to remove the account and add it back:

1. Settings → Apps → Mail → Mail Accounts
2. Tap the account, then Delete Account
3. Add it again with the same credentials

Nothing on the server is affected - your mail is re-downloaded, minus the accumulated local attachment cache. Do check you know the password before you start.

Restart your iPhone

A restart clears temporary memory caches and some system caches. It is the one thing that reliably makes the System Data figure drop, often by a few hundred megabytes.

Hold the side button and either volume button, drag the slider, wait, then power back on.

It does not clear Safari’s website data or any app’s stored cache - but it is free, takes thirty seconds, and is worth doing after everything above.

Three things that don’t work

The “hold power then press Cancel” trick. A long-running rumour claims this clears RAM. It does nothing. The version of this trick that did something applied to iPhones with a physical Home button, and even then it only cleared memory, not storage.

Apps that claim to clear your cache. The App Store has plenty. They cannot do it, for the sandbox reason above. What they can generally see is your photo library - which is a legitimate thing to clean, but not what they advertised. More on judging those in what iPhone cleaner apps can and can’t do.

Trying to clear System Data directly. There is no way, and there is no hidden menu. System Data is the leftover bucket - caches, logs, Siri voices, streaming buffers, partly downloaded iOS updates. iOS shrinks it on its own when it needs room. Clearing Safari data and restarting is the only user-facing action that reliably moves it - the full breakdown is in what System Data is and how to shrink it.

So how much did you actually get back?

Add it up. On a typical well-used iPhone:

Best case, a few gigabytes - and the Messages line is doing most of the work, which is not really a cache at all.

Now open Settings → General → iPhone Storage and look at the top of the list.

On the overwhelming majority of iPhones, it says Photos, and the number beside it is larger than everything you just cleared put together. Often by a factor of twenty.

Where the space actually went

Photos is at the top of that list not because you took too many photos, but because of how a modern iPhone takes them:

• You shot the same picture four times to get one good one, and all four stayed.
• One minute of 4K video is roughly 400 MB. Ten minutes of a school concert outweighs a thousand photos.
• Screen recordings are worse still - a few minutes of 60fps capture, kept forever after you sent it once.
• Every Live Photo carries a video, usually two thirds of what the shot weighs.
• The same image arrives twice - once over WhatsApp, once by AirDrop - and both stay.
• Screenshots are never deleted. Nobody has ever gone back and tidied up a screenshot of a 2021 boarding pass.

The Photos app cannot help you here. It has no idea which of your images are near-identical, and it will not tell you which video is 2 GB. You need something that sorts by what is actually costing you space.

That is what Declutta does. It scans for duplicates, near-identical shots, oversized videos, screen recordings, bursts and blurry frames, tells you what each category would give back, and removes only what you confirm. Scanning is free, and it runs entirely on the phone - free, with no ads and no paywall, no account, and nothing leaving the device.

The full walkthrough, in order of space freed per minute of effort, is in how to free up space on iPhone without deleting photos you care about.

What any iPhone cleaner can and cannot touch

Worth being explicit, because this is exactly where cleaner apps oversell themselves.

No third-party iPhone app can clear another app’s cache. Not Declutta, not any of them. The sandbox is absolute, and an app store listing promising otherwise is describing something iOS does not permit.

What a third-party app can legitimately reach, with your permission, is your photo and video library. On most iPhones that is also where 60-80% of the used space is. So the honest pitch is not “we clean everything” - it is “we clean the one thing that is actually big, and Apple has no tool for.”

If you want the caches gone, the methods above are the complete set. If you want the tens of gigabytes back, that is a photo library problem.

Frequently asked questions

How do I clear the cache on my iPhone?

There is no single button. Clear Safari’s cache in Settings → Apps → Safari → Clear History and Website Data. Other apps each keep their own cache and have to be cleared from inside that app’s own settings, or by offloading the app in Settings → General → iPhone Storage. iOS has no system-wide cache clear because every app’s cache is sealed inside its own sandbox.

Does clearing the cache on an iPhone delete anything important?

Clearing Safari’s history and website data signs you out of every site you were logged into and clears saved cookies, but it does not touch bookmarks, saved passwords or your Reading List. Offloading an app keeps all of that app’s documents and data and restores them when you reinstall it.

How much space does clearing the cache actually free?

Usually between 100 MB and 1.5 GB across Safari and a handful of heavy apps. It is real, but it is rarely the reason a phone is full. On most iPhones the photo and video library is ten to fifty times larger than every cache combined.

Why is there no Clear Cache button in iPhone settings?

Because iOS sandboxes every app. An app’s cache lives inside a container that no other app, and no system-wide settings screen, is allowed to open and empty. Apple’s answer is Offload App, which deletes the app binary and its cache while keeping your data.

How do I clear cookies on my iPhone without losing my history?

Go to Settings → Apps → Safari → Advanced → Website Data, then swipe to remove individual sites or tap Remove All Website Data. This clears cookies and cached site data while leaving your browsing history intact.

Can a cleaner app clear my iPhone’s cache for me?

No, and any app claiming to is misleading you. The sandbox that stops one app reading another app’s cache applies to cleaner apps too. What a third-party app can legitimately reach is your photo and video library, which is where the space usually is.

What is System Data on iPhone and can I clear it?

System Data is the leftover bucket in Settings → General → iPhone Storage - caches, logs, Siri voices, streaming buffers and update files. There is no way to clear it directly. It shrinks on its own when the phone needs room, and clearing Safari data plus restarting is the only user-facing thing that reliably reduces it.

Does restarting an iPhone clear the cache?

It clears temporary memory caches and some system caches, which is why System Data often drops by a few hundred megabytes after a restart. It does not clear Safari’s website data or any app’s stored cache.

What is the difference between offloading and deleting an app?

Offload App removes the app itself and its cache but keeps every document and setting, so reinstalling restores you exactly where you were. Delete App removes the app and all of its data permanently.

My iPhone still says storage is full after clearing everything. What now?

Open Settings → General → iPhone Storage and look at what is at the top of the list. On the overwhelming majority of iPhones it is Photos, and no amount of cache clearing will move it. Duplicate photos, large videos, screen recordings and Live Photos are where the gigabytes actually are.

The short version

Clear Safari’s history and website data, or just its Website Data if you would rather stay logged in. Offload the two or three apps at the top of your storage list. Set Messages to keep one year instead of forever. Re-add your Mail account. Restart. That is every cache on an iPhone that can actually be cleared, and it is worth about a gigabyte.

Then check what is at the top of Settings → General → iPhone Storage. If it says Photos and the number is in the tens of gigabytes, the cache was never the problem.

Get Declutta free → · Free, no ads, no paywall. See what’s recoverable before you delete anything.