Your iPhone used to be fast. Now it hesitates when you open apps, the keyboard lags behind your typing, and Safari takes forever to load pages. You're not imagining it. iPhones genuinely slow down over time — but the reasons aren't what most people think, and the fixes are almost always free.
I'm a repair technician. I see slow iPhones every day. Here's what's actually causing it, 10 things you can do right now that cost nothing, what you should absolutely avoid, and when the problem is hardware that needs professional attention.
Why iPhones Slow Down
There are four main reasons your iPhone isn't as fast as it used to be, and none of them mean Apple is secretly sabotaging your phone to make you buy a new one.
iOS updates on older hardware
Every major iOS update is designed for the newest chips. When Apple releases iOS 18, it's optimised for the A17 Pro and A18 chips. Your iPhone 11 with an A13 chip will run it — but it has to work harder to do the same things. Each new iOS version adds features that demand more processing power, more RAM, and more storage. After 2-3 major updates, your older iPhone is genuinely doing more work with the same hardware. It's not planned obsolescence — it's software growing faster than hardware can keep up.
Full or nearly full storage
This is the most common cause of a slow iPhone and the one people overlook the most. iOS needs free space to function properly. It uses storage for temporary files, app caches, system processes, and iOS updates. When your storage is above 90% full, everything slows down — apps take longer to launch, the camera hesitates before taking photos, and switching between apps becomes painful. If your iPhone has less than 5GB free, that's your problem.
Background App Refresh eating resources
Every app you've installed that has Background App Refresh enabled is periodically waking up, checking for new data, and using CPU and battery in the background. Social media apps are the worst offenders — Instagram, Facebook, TikTok, and Snapchat are constantly refreshing feeds, downloading content, and tracking location even when you're not using them. Multiply that by 40-50 apps and your iPhone is doing an enormous amount of work you never asked it to do.
Degraded battery triggering performance throttling
This is the big one. Since iOS 10.2.1, Apple has included a feature called "performance management" that deliberately slows down your iPhone's CPU when the battery is degraded. The reason is legitimate — an old battery can't deliver peak power reliably, and without throttling, your phone would randomly shut down during demanding tasks. But the result is a noticeably slower phone. If your Battery Health shows a maximum capacity below 80%, your iPhone is almost certainly being throttled.
10 Free Fixes — Do These Right Now
Every one of these is free, takes less than 5 minutes, and doesn't require any technical knowledge. Start from the top and work your way down.
1. Check Your Storage — and Free Up Space
This is the first thing to check because it's the most common cause of slowness. If you're above 90% full, this is likely your main problem.
Delete old photos and videos you've already backed up, remove apps you haven't opened in months, and clear out old message threads with large attachments. iOS helpfully shows you a breakdown of what's using your storage and gives recommendations for freeing space.
How to do it: Settings > General > iPhone Storage. Wait for it to load fully (it calculates sizes for each app). Aim for at least 5-10GB of free space. Tap any app to see how much storage it uses and the option to offload or delete it. Pay special attention to Photos, Messages, and any streaming apps that cache offline content.
2. Turn Off Background App Refresh
Most apps don't need to refresh in the background. Your email will still arrive when you open the Mail app. Instagram doesn't need to pre-load your feed 50 times a day while you're working. Disabling this for non-essential apps frees up CPU cycles and saves battery life.
Keep it on for apps where real-time notifications matter — messaging apps, banking apps, navigation. Turn it off for everything else.
How to do it: Settings > General > Background App Refresh. You can disable it globally or go through the list app by app. I recommend going app by app — keep it on for 5-10 essential apps and turn it off for everything else.
3. Clear Safari Cache and Data
Safari accumulates cached data, cookies, and browsing history over time. On an iPhone that's been used for a year or more without clearing, this can amount to several gigabytes of data. Clearing it frees up storage and can noticeably improve Safari's performance.
You will be logged out of websites and your browsing history will be cleared. If that's a problem, at least clear the cache without clearing history by closing all your Safari tabs first (long-press the tab switcher button and tap "Close All Tabs").
How to do it: Settings > Apps > Safari > Clear History and Website Data. For a less aggressive option, go to Settings > Apps > Safari > Advanced > Website Data and remove data from specific sites.
4. Restart Your iPhone
It sounds too simple to work, but restarting your iPhone clears temporary memory, stops any misbehaving background processes, and gives iOS a fresh start. If you haven't restarted your phone in weeks or months, cached processes and memory leaks build up and cause genuine slowness.
A restart is not the same as locking your phone. Pressing the side button to turn off the screen doesn't restart it. Your iPhone stays running with all the same processes.
How to do it: Hold the Side button and either Volume button until "Slide to Power Off" appears. Slide it. Wait 30 seconds, then hold the Side button to turn it back on. Do this at least once a week as a habit.
5. Disable Unnecessary Location Services
Many apps request "Always" access to your location when they only need it while you're actively using them — or don't need it at all. A weather app checking your location in the background, a shopping app tracking you for "personalised offers," and a social media app logging where you go — these all use GPS hardware, which drains battery and consumes processing power continuously.
How to do it: Settings > Privacy & Security > Location Services. Go through each app. Change "Always" to "While Using" for apps that only need your location when open (maps, ride-sharing, weather). Change to "Never" for apps that have no business knowing where you are (games, calculators, shopping apps). Leave Location Services itself turned on — just restrict which apps can use it.
6. Reduce Motion and Transparency Effects
iOS uses animations for everything — opening apps, switching between them, parallax effects on the home screen, blur and transparency effects throughout the interface. These look nice but they require GPU processing power. On older iPhones, disabling them makes the interface feel noticeably snappier because the phone isn't rendering animations it struggles to keep smooth.
How to do it: Settings > Accessibility > Motion > turn on Reduce Motion. Also go to Settings > Accessibility > Display & Text Size > turn on Reduce Transparency. The interface will look slightly different (less blur, crossfade instead of zoom animations) but it will feel faster.
7. Turn Off Automatic Downloads
By default, iOS automatically downloads app updates, music, books, and apps purchased on other devices. This runs in the background, uses network bandwidth, and consumes CPU and storage. If you're on a phone with limited storage or an older processor, these background downloads compete with the apps you're actually trying to use.
How to do it: Settings > App Store > turn off App Downloads, App Updates, and In-App Content under Automatic Downloads. You can still update apps manually whenever you want — just open the App Store, tap your profile icon, and pull down to check for updates.
8. Check Battery Health
This isn't a "fix" so much as a diagnosis. If your battery's maximum capacity is below 80%, Apple's performance management is actively throttling your CPU speed. Understanding this tells you whether your slow phone is a software problem (fixable for free) or a hardware problem (fixable with a battery replacement).
If you see a message that says "Performance management has been applied" or your maximum capacity is in the 70s, your battery is the primary reason your phone is slow. No amount of settings changes will fully fix it — you need a new battery.
How to do it: Settings > Battery > Battery Health & Charging. Check "Maximum Capacity" — 100% is new, 80% or below means it's significantly degraded. Also check if "Peak Performance Capability" says anything other than "Your battery is currently supporting normal peak performance."
9. Reset All Settings
Over time, accumulated settings, broken configurations, and corrupted preferences can cause weird behaviour and slowdowns. Resetting all settings returns every iOS setting to its factory default without deleting any of your data, apps, photos, or messages. It resets Wi-Fi passwords, wallpapers, notification preferences, and privacy settings — but your actual content stays intact.
This is the nuclear option among free fixes, so try the others first. But if nothing else has helped, this often resolves persistent slowness caused by corrupted system settings.
How to do it: Settings > General > Transfer or Reset iPhone > Reset > Reset All Settings. You'll need to enter your passcode. Your phone will restart and you'll need to reconnect to Wi-Fi and reconfigure some preferences, but all your data remains.
10. Update to the Latest iOS Version
This seems counterintuitive — I just said iOS updates can slow older phones. But within a major version, Apple's point releases (like iOS 18.1, 18.2, 18.3) consistently improve performance and fix bugs. If you're on iOS 18.0 and it's been sluggish, iOS 18.4 probably runs better on the same hardware. Apple uses these updates to optimise performance, fix memory leaks, and resolve issues that cause slowdowns.
Always stay on the latest point release of whatever major iOS version you're running. Only be cautious about major upgrades (like going from iOS 17 to iOS 18) on very old hardware.
How to do it: Settings > General > Software Update. Download and install any available update. Make sure you're on Wi-Fi and have at least 50% battery (or plug in during the update). If storage is full, you may need to free up space first — iOS updates typically need 2-5GB of free space.
What NOT to Do
iPhone cleaner apps are scams. Apps that claim to "clean RAM," "remove junk files," "boost performance," or "optimise your iPhone" are lying to you. iOS manages its own memory automatically. Third-party apps cannot access other apps' data or caches due to Apple's sandboxing. These apps run a fake "scan," show you scary numbers, and then ask you to pay for the "pro" version. The app itself uses more resources than it could ever free up. Delete any you have installed.
Actually Helps
- Freeing storage — the single most impactful free fix for most slow iPhones
- Disabling Background App Refresh — immediate improvement in responsiveness and battery life
- Restarting regularly — clears memory leaks and stuck processes
- Battery replacement — restores full CPU speed on throttled phones
- Keeping iOS updated — point releases fix performance bugs
Waste of Time / Scam
- "iPhone cleaner" apps — all scams, every single one
- "RAM booster" apps — iOS manages memory automatically, these do nothing
- Force-closing all apps — actually makes your phone slower because iOS has to reload them from scratch
- Putting your phone in rice — unrelated to speed, but while we're here: this doesn't work either
- Paid "optimisation" subscriptions — recurring scams that do nothing your settings can't do for free
When It's Hardware: Battery Replacement
If you've tried all 10 free fixes above and your phone is still slow, and your Battery Health shows maximum capacity below 80%, a battery replacement is almost certainly the fix. It's one of the most cost-effective repairs we do.
Apple's performance management throttles your CPU to prevent unexpected shutdowns when the battery can't deliver peak power. A new battery removes the throttle entirely. Customers consistently tell us their phone "feels like new" after a battery swap — because it's now running at full speed again instead of being held back.
This matters because people often assume they need a new phone when all they need is a $80-$120 battery replacement. A genuine battery restores full performance, and the repair takes under an hour.
Not all replacement batteries are equal. Cheap aftermarket batteries from eBay and Amazon often have lower actual capacity than advertised and can trigger iOS warnings. Read our guide on fake iPhone batteries before getting a replacement anywhere.
When to Upgrade
Sometimes a slow iPhone is telling you it's time. Here's how to think about it honestly:
Consider upgrading if: your iPhone is 4-5+ years old, no longer receives iOS updates (meaning no security patches), the battery is degraded AND the screen or other components need repair too, or the total repair cost exceeds 50-60% of a replacement device. An iPhone that no longer gets iOS updates is a security risk regardless of how fast it feels.
Don't rush to upgrade if: your phone still receives iOS updates, the only problem is speed (try the fixes above first), or a battery replacement would solve the issue. A $100 battery replacement that gives you another 2 years is far better value than a $1,800 new iPhone.
A refurbished iPhone that's 1-2 generations old is almost always better value than buying brand new. You get 90% of the performance at 40-50% of the price, and a properly refurbished phone with a new battery and screen will last just as long. We stock refurbished iPhones with warranty that outperform the "as new" options on eBay and Marketplace.
Quick Summary
- Check storage (Settings > General > iPhone Storage) — free up space if above 90%
- Turn off Background App Refresh for non-essential apps
- Clear Safari cache and close old tabs
- Restart your phone — if you haven't in weeks, do it now
- Restrict location services to "While Using" or "Never" for most apps
- Enable Reduce Motion and Reduce Transparency in Accessibility
- Disable automatic downloads in App Store settings
- Check Battery Health — below 80% means you're being throttled
- Reset All Settings if nothing else has worked (your data stays safe)
- Update iOS to the latest point release
If you've done all of this and your phone is still slow, the problem is hardware — most likely the battery. Bring it in and we'll diagnose it properly.
iPhone still slow after trying everything?
We'll diagnose the real problem and give you honest advice — no pressure, no unnecessary repairs.
Worried about aftermarket batteries? Read our guide on fake iPhone batteries before getting a replacement from anyone.