iPhone 13 Problems in 2026: Lag, Battery Drain and Fixes

“So bad.” That was how one iPhone 13 owner described their phone in an Apple Community thread in August 2026, right after updating to iOS 26.6, before asking whether they could go back to the old version. Lag after updates is the iPhone 13 problem you hear about most this year, followed by a battery that no longer gets through the day and heat on the charger.

Most of it can be fixed, and usually for less than you’d expect. The phone has an A15 Bionic chip and 4GB of RAM. It is fully supported by iOS 27, which runs on everything from the iPhone 11 onward (see our iOS 27 supported iPhones list). It just has less memory headroom than newer models, and you notice that as apps and widgets get heavier.

Check the battery before anything else

Most iPhone 13 batteries are now four to five years old. Lithium-ion cells lose capacity with every charge cycle, and a worn one can’t deliver peak power. To stop the phone shutting down unexpectedly, iOS may then hold performance back. So a tired battery doesn’t only mean short battery life. It can make the whole phone feel slow.

The signs: 20% gone in an hour of light use, the phone switching off at 15–20%, or everything feeling throttled.

1. Open Settings › Battery › Battery Health (called Battery Health & Charging on older iOS versions). Maximum Capacity under 80%, or the words Service Recommended, means the battery is due for replacement.
2. In Settings › Battery, look for an app with unusually high background activity.
3. Use Low Power Mode on days you need to stretch it.
4. Don’t leave it sitting at 100% on a hot charger. Optimized Battery Charging helps with this.

Is a new battery worth it? If the rest of the phone is in good shape, usually yes. It brings back full performance and a full day of use for far less than a new phone costs. Go to an Apple Store, an Apple Authorised Service Provider, or use Apple’s Self Service Repair, so the part shows as genuine in Settings › General › About › Parts and Service History. A third-party battery shows up there as “Unknown Part”, and that can knock down the resale price. Our battery health and parts history guide explains each message you might see.

Slow for days after iOS 26.6 or iOS 27

If the battery is healthy and the phone still lags (keyboard delay, stutter when you swipe, apps a beat slower to open), the update is the likely cause.

Apple’s iOS 26.6 update optimised the Spotlight index to get ready for iOS 27, and iOS 27 then rebuilt search across apps, Photos and Mail. On a phone holding years of photos and messages, that takes a lot of processor time. A community expert in the same Apple thread said indexing after an update can take around four days, and longer for iOS 26.6.

Going back isn’t possible. Apple stops signing older iOS versions shortly after an update, so a restore just puts the current one back on.

1. Plug the phone in overnight on Wi-Fi for three or four nights running so indexing can finish.
2. Free space in Settings › General › iPhone Storage. Keep at least 10% free: offload apps you don’t use and clear big message attachments.
3. Turn on Settings › Accessibility › Motion › Reduce Motion and take animated or live widgets off the Home Screen.
4. Switch off Settings › General › Background App Refresh for apps that don’t need it.
5. Force restart: press and release volume up, press and release volume down, then hold the side button until the Apple logo appears.
6. Still slow after a week? Back up, erase with Settings › General › Transfer or Reset iPhone › Erase All Content and Settings, and set it up fresh.

Freezes and the widget crash on iOS 27

Some of it is plain bugs. Cybernews reported an iPhone 13 Pro owner whose whole interface crashed when editing Home Screen widgets, until a restart. It also noted slow or unresponsive screens on older iPhones as well as new ones. Apple’s iOS 27.0.1 (28 September 2026) fixed a touchscreen freeze that happened when Notification Center and Control Center were opened at the same time.

• Install the newest update in Settings › General › Software Update.
• If editing widgets crashes the interface, remove the widget that sets it off and add it back after the next update.
• Update any app that freezes. Developers tend to ship iOS 27 fixes in the weeks after release.

Bugs affecting other models are in our iOS 27 problems page.

Warm while charging

Heat in the first few days after an update is usually the same indexing that causes the lag, and it settles down. Heat that doesn’t go away usually comes from gaming or streaming on the charger, a thick case, or a worn battery.

1. Take the case off while charging and leave heavy apps alone until it’s done.
2. Use an Apple or MFi-certified Lightning cable and a decent adapter.
3. Check Settings › Battery for an app that never stops running in the background.
4. Hot while idle with a healthy battery? Book Apple diagnostics.

Green tint and lines on the screen

A green or pink tint, flickering lines, or a screen that turns green after a restart is rarely something software can fix. Force restart and update first anyway. If the tint is still there, the display is faulty. On a used phone it can also mean a cheap replacement screen. Look in Parts and Service History for an “Unknown Part” display and get an official screen repair quote.

Settings that take load off the A15

With indexing finished and a healthy battery, a few settings cut the work the chip does every second. None of them delete anything, and you can turn them all back.

• Reduce Transparency in Settings › Accessibility › Display & Text Size removes the blur effects the newer iOS design leans on. Older GPUs like that.
• Fewer widgets. Each live widget refreshes in the background. One page of them, not three.
• Siri suggestions. In Settings › Siri (or Apple Intelligence & Siri), turn off suggestions for apps you never open from search.
• Location Services. In Settings › Privacy & Security › Location Services, set rarely used apps to “Never” or “While Using”.
• Photos. If iCloud Photos is still uploading thousands of items, the phone stays busy. Let it finish on Wi-Fi and power.

Skip the “cleaner” and “booster” apps. iOS manages memory itself. Swiping apps closed all the time makes them reload from scratch, which costs more battery and time than leaving them suspended.

Repair it or move on?

Keep it if the screen and body are fine and a new battery sorts out the speed. It will run iOS 27 well for everyday use. Think about upgrading if it needs a screen and a battery, if a 128GB model is out of space, or if you want features that need a newer chip.

Find out what yours is worth first with our iPhone trade-in value guide. Selling privately? Follow our guide to selling a phone safely.

Buying one used? Check these

There are so many iPhone 13s on the used market that they attract scams: the wrong storage size, swapped parts, carrier locks, and phones still signed in to someone’s Apple Account.

• Run a model, colour, storage and Find My check to confirm the listing matches the phone.
• Use the Apple full GSX report for warranty, purchase country, lock and blacklist status.
• In person, open Battery Health and Parts and Service History, and make sure Find My is off.