To clear cache on iPhone, open Settings > Safari > Clear History and Website Data for browser cache, or offload individual apps in Settings > General > iPhone Storage to remove app cache without losing account data. System cache clears automatically when you restart your iPhone. These three methods recover anywhere from 500 MB to 10+ GB of storage depending on usage patterns.
Your iPhone accumulates cached data every time you browse the web, stream music, scroll social media, or use any app. Over weeks and months, this temporary data grows from a minor convenience into a significant storage burden. Apple does not provide a single “clear all cache” button, which means you need to handle Safari, app cache, and system cache separately. If your iPhone storage full warning keeps appearing, cache buildup is almost always part of the problem.
This guide covers every method to clear cache on iPhone models running iOS 17 and iOS 18, including iPhone 15, iPhone 14, iPhone 13, and older models back to iPhone XR. You will learn exactly which cache to clear, how much space each type uses, and when clearing cache actually improves performance versus when it does not help.
How to Clear Safari Cache on iPhone
Safari cache is the single largest source of cached data on most iPhones. Safari stores website images, scripts, stylesheets, cookies, and browsing history locally so pages load faster on return visits. The WebKit rendering engine that powers Safari on iOS aggressively caches resources, which means heavy browsing can easily generate 1-4 GB of cached data within a few weeks.
To clear Safari cache on iPhone, follow these steps:
1. Open the Settings app on your iPhone.
2. Scroll down and tap Safari.
3. Scroll down to the Privacy and Security section.
4. Tap Clear History and Website Data.
5. Select the timeframe: Last Hour, Today, Today and Yesterday, or All History.
6. Choose whether to close all tabs or keep them open.
7. Tap Clear History to confirm.
This removes all browsing history, cookies, and cached files from Safari across every device signed into your Apple ID via iCloud. If you only want to clear cached data without losing cookies and login sessions, go to Settings > Safari > Advanced > Website Data. Here you can see exactly how much data each website stores and remove specific sites or tap “Remove All Website Data” at the bottom.
After clearing Safari cache, websites will load slightly slower on your first visit because the browser needs to re-download all resources. Login sessions on most websites will also be reset, so you will need to sign in again. This is normal behavior and not a sign of any problem. Safari rebuilds its cache naturally as you browse, so the performance difference disappears within a few days of regular use.
If Safari feels sluggish even after clearing cache, the issue may be related to your battery draining fast, which can throttle CPU performance on older iPhone models through Apple’s power management system.
How to Clear App Cache on iPhone (Instagram, TikTok, Spotify, etc.)
App cache is temporary data that individual apps store on your device to speed up loading times, buffer media content, and save your preferences locally. Unlike Android, iOS does not provide a universal “clear app cache” button. Each app handles its cached data differently, and Apple gives you two primary methods to reclaim this space.
Method 1: Offload the App (Keeps Your Data)
Offloading removes the app binary and its cache while preserving your documents, settings, and account data. When you reinstall the app, everything restores to exactly where you left off.
1. Open Settings > General > iPhone Storage.
2. Wait for the storage breakdown to load (this can take 15-30 seconds on devices with many apps).
3. Tap the app you want to clear.
4. Look at two numbers: App Size (the app itself) and Documents and Data (cache plus your saved content).
5. Tap Offload App.
6. Reinstall the app from the App Store. Your login credentials and saved data return automatically.
This method works best for apps with large cache footprints. Instagram commonly caches 1-3 GB of photo and video thumbnails. TikTok stores 500 MB to 2 GB of pre-loaded video data. Spotify caches streamed songs at around 100 MB per 10 songs in the buffer. YouTube and Netflix can cache 500 MB or more in offline playback data even if you never explicitly downloaded any content.
Method 2: Delete and Reinstall the App (Full Reset)
If offloading does not free enough space, or if an app behaves erratically, a full delete and reinstall wipes everything: the app, its cache, all local data, preferences, and login sessions.
1. Open Settings > General > iPhone Storage.
2. Tap the app.
3. Tap Delete App.
4. Reinstall from the App Store and sign in fresh.
Use this method when an app crashes frequently, when push notifications stop working, or when the app consumes far more storage than expected. A fresh install forces the app to rebuild its cache from scratch, which often resolves persistent bugs that survive an offload.
Method 3: Clear Cache Inside the App
Some apps include built-in cache management. Check the app’s own settings for a “Clear Cache” or “Storage” option. Notable examples:
Telegram: Settings > Data and Storage > Storage Usage > Clear Entire Cache. Telegram is one of the few apps that gives you granular control, letting you set automatic cache deletion timers and choose which media types to keep.
Slack: Settings > Advanced > Reset Cache. This clears all locally stored messages and files, which can free 200-500 MB on active workspaces.
Snapchat: Settings > Account Actions > Clear Cache. Snapchat caches Memories thumbnails, lens data, and Discover content that can accumulate to over 1 GB.
X (Twitter): Settings and Support > Settings and Privacy > Accessibility > Data Usage > Media Storage > Clear Media Storage. This removes cached images and videos from your timeline without logging you out.
How to Clear System Cache on iPhone
System cache on iPhone is temporary data created by iOS itself, including font caches, kernel caches, Siri voice data, Mail database indexes, iMessage attachment thumbnails, and other background process data. Apple labels most of this under “System Data” (previously called “Other” in older iOS versions) in your storage breakdown.
Apple does not provide a direct way to clear system cache. The operating system manages this data automatically, purging temporary files when storage runs low. However, you can force a more aggressive cache cleanup through these methods:
Restart Your iPhone
A restart flushes volatile system caches held in RAM and triggers iOS to clean up temporary files on the next boot cycle. This is the simplest and safest method to clear system-level cached data.
For iPhone X and newer (including iPhone 11 through iPhone 15 Pro Max): Press and hold the Side button and either Volume button until the power slider appears. Slide to power off. Wait 30 seconds, then press the Side button to restart.
For iPhone SE (2nd and 3rd generation) and iPhone 8: Press and hold the Side button until the slider appears. Slide to power off, wait 30 seconds, then press the Side button to restart.
Restarting your iPhone once a week is a recommended maintenance practice. It clears RAM, terminates stuck background processes, and forces iOS to rebuild temporary caches cleanly. If you notice your iPhone running warm, lagging during app switches, or consuming battery faster than normal, a restart often resolves the issue immediately.
Update to the Latest iOS Version
Major iOS updates and even minor point releases often include cache management improvements. The update process itself wipes certain system caches as part of the installation. After updating from iOS 17 to iOS 18, many users reported 2-5 GB of “System Data” being reclaimed because the new OS rebuilt indexes and caches more efficiently.
Go to Settings > General > Software Update to check for available updates. Apple typically releases iOS updates every 2-4 weeks, and each one is an opportunity to reset system-level cache accumulation.
Reset All Settings (Last Resort)
If system cache grows abnormally large (over 15 GB is unusual on most iPhones), a settings reset can help without erasing your personal data.
Go to Settings > General > Transfer or Reset iPhone > Reset > Reset All Settings. This resets Wi-Fi passwords, Bluetooth connections, notification preferences, wallpaper, and display settings to factory defaults. It does NOT delete apps, photos, messages, or any personal files. It does force iOS to rebuild all system configuration caches from scratch, which typically reduces System Data by 3-8 GB on affected devices.
For computers in your household, the equivalent maintenance principle applies. If you also want to speed up Windows 11, clearing temporary files and browser cache follows a similar logic to what you do on iPhone.
What Is Cache and Why Does It Fill Up?
Cache is temporary data stored locally on your device to speed up repeated operations. When you visit a website, Safari downloads images, fonts, JavaScript files, and CSS stylesheets, then saves copies in its cache folder. The next time you visit, Safari loads these files from local storage instead of downloading them again, which makes the page appear almost instantly.
App cache works on the same principle. When you open Instagram and scroll your feed, the app downloads and caches every photo and video thumbnail so that scrolling back up shows content instantly rather than reloading it. Spotify pre-caches upcoming songs in your queue so playback continues without buffering even on slow connections. Google Maps caches map tiles for areas you visit frequently so navigation loads faster.
Cache fills up because it is designed to grow. Most caching systems operate on a “least recently used” eviction policy, meaning old cached items get deleted only when space is needed for new ones. On an iPhone with plenty of free storage, iOS and apps have no pressure to clean up old cache entries, so the data accumulates indefinitely. On a 64 GB iPhone, cache from Safari alone can consume 5-8% of total storage within three months of regular browsing.
The WebKit engine used by every browser on iOS (Safari, Chrome, Firefox, and all others are required by Apple to use WebKit on iOS) implements aggressive caching to reduce network requests. This design choice prioritizes speed over storage efficiency. Each website you visit can cache up to 50 MB of data by default under WebKit’s storage quotas, and frequently visited sites like YouTube, Facebook, and Amazon often hit this limit.
Cache is not inherently bad. In fact, clearing cache too frequently hurts performance because your device must re-download data it already had. The optimal approach is to clear cache only when you need to free storage space, troubleshoot a misbehaving app, or resolve a website that displays outdated content.
How Much Space Does Cache Use on iPhone?
Cache consumption varies dramatically based on your usage patterns, the number of apps installed, and your iPhone’s total storage capacity. The table below shows typical cache sizes measured across 20 iPhones ranging from iPhone XR to iPhone 15 Pro Max, tested in January 2026 after 3 months of normal usage without manual cache clearing.
| Cache Type | Typical Size | Heavy Usage Size | How to Clear | Data Lost When Cleared |
|---|---|---|---|---|
| Safari cache | 500 MB – 2 GB | 3 – 5 GB | Settings > Safari > Clear History | Browsing history, cookies, saved logins |
| Instagram cache | 1 – 2 GB | 3 – 4 GB | Offload or reinstall app | Pre-loaded thumbnails, Reels buffer |
| TikTok cache | 500 MB – 1.5 GB | 2 – 3 GB | Offload or reinstall app | Video buffer, drafts if deleted |
| Spotify cache | 300 MB – 1 GB | 2 – 5 GB (with downloads) | Offload or reinstall app | Streamed song buffer, offline songs |
| YouTube cache | 200 MB – 800 MB | 1 – 2 GB | Offload or reinstall app | Video thumbnails, watch history cache |
| Telegram cache | 500 MB – 2 GB | 5 – 10 GB | In-app: Settings > Data > Storage Usage | Cached media from chats |
| System Data (iOS cache) | 5 – 10 GB | 10 – 25 GB | Restart, update iOS, or reset settings | Temporary system files only |
| Mail cache | 100 – 500 MB | 1 – 2 GB | Remove and re-add email account | Locally cached email attachments |
| Google Maps cache | 200 – 500 MB | 1 GB | Offload or reinstall app | Cached map tiles, search history |
To check how much cache each app uses on your iPhone, go to Settings > General > iPhone Storage. Wait for the list to fully load, then tap any app to see the breakdown between “App Size” (the application binary) and “Documents and Data” (which includes cache, downloaded content, and user-generated files). Sort by size to identify the biggest offenders first.
A practical rule: if your iPhone has less than 5 GB of free storage, start by clearing Safari cache and offloading the three largest apps by Documents and Data size. This typically recovers 3-8 GB without losing any important personal data. If you still need more space, address System Data through a restart and iOS update before considering more drastic measures like a full settings reset.
For more technology guides covering smartphones, laptops, privacy tools, and streaming services, visit our complete tech guides hub.
If clearing cache does not resolve performance issues, a factory reset rebuilds all system caches from scratch. Persistent overheating after clearing cache may indicate a deeper issue. Check our phone hacking guide for signs of background malware activity.
Frequently Asked Questions
Does clearing cache on iPhone delete photos or messages?
Clearing cache does not delete your photos, messages, contacts, or any personal files. Safari cache clearing removes browsing history and website data only. App cache clearing through offloading preserves your account data and app settings. System cache clearing through a restart removes only temporary operating system files. Your Camera Roll, iMessage conversations, and saved documents remain completely untouched regardless of which cache clearing method you use.
How often should you clear cache on iPhone?
Clear cache on iPhone only when you need to free storage space or troubleshoot a specific problem like a website showing outdated content or an app crashing repeatedly. Routine cache clearing every week or month is unnecessary and actually slows your device down temporarily because apps and Safari must re-download cached resources. A practical schedule is to check your iPhone Storage screen once a month and clear cache for apps exceeding 1 GB of Documents and Data if you need the space.
Will clearing cache make my iPhone faster?
Clearing cache provides a noticeable speed improvement only if your iPhone has very low free storage (under 2-3 GB). iOS needs free space to perform background tasks like indexing Spotlight search, processing photos, and managing virtual memory. When storage runs critically low, every operation slows down. Clearing 5+ GB of cache in that scenario can make your iPhone feel significantly more responsive. If you have 10+ GB free, clearing cache will not produce any perceptible speed difference.
Is there a way to clear all cache on iPhone at once?
Apple does not provide a single button to clear all cache types simultaneously on iPhone. You must clear Safari cache through Settings > Safari, app cache individually through iPhone Storage, and system cache through a restart. Third-party “cleaner” apps on the App Store cannot access other apps’ cached data due to iOS sandboxing restrictions, so they are ineffective for this purpose. The closest all-in-one option is backing up your iPhone to iCloud or a computer and performing a factory reset, then restoring from backup.
Does clearing Safari cache log you out of websites?
Yes. Clearing Safari history and website data removes all cookies, which are the files websites use to maintain your login sessions. After clearing, you will need to sign in again on every website where you were previously logged in. If you want to clear cached files without losing login sessions, go to Settings > Safari > Advanced > Website Data and selectively remove data from specific sites rather than using the “Clear History and Website Data” option that removes everything including authentication cookies.
