Slow performance and lag after iOS 26 update on iPhone

Same issues, 1TB 15 Pro.. iOS 26.0.1, running caseless 24/7.

What fixed it for me is to completely turn off Apple Intelligence. Phone doesn’t get near as hot and doesn’t suffer through thermal throttling issues anymore. Up until that I was experiencing severe lag and then thermal throttling when charging and also when connected to wired CarPlay. No VPN profiles, more than 50% left in storage. Tried turning on reduce transparency, slightly helped. Try turning off Apple Intelligence.

shianne277 wrote:

A few days? But after updating mine it’s still being slow and laggy for like a month now and I jsut updated it to the iOS 26.01 and it’s still so slow and laggy and kicking me off apps

Check your battery health at Settings > Battery > Battery Health > Maximum Capacity. If it is below 80%, then you will need your battery replaced, and that would have been true on iOS 18 as well. You may be experiencing increased demands on a battery that is not capable of providing the power and there may also be a message under Peak Performance Capability that also says that the performance is being limited.

iPhone battery and performance - Apple Support

sma333 wrote:

I used apple support which was very helpful. It took a while but what finally fixed it was to delete VPN apps on iphone 13

While this is apparently resolved, what does Apple suggest for VPN if on public wifi?

Apple has no opinion on VPN. Experienced users in this forum do, however. First, you don’t need VPN on public Wi-Fi, because all communication to and from an iPhone is end to end encrypted. Your iPhone also “lies” about its Wi-Fi address when connecting to unknown networks, so your iPhone can’t be tracked by its Wi-Fi address. Using VPN is LESS secure that no VPN, because when you use VPN there is a middleman, the VPN provider, who knows everywhere you connect to, and thus can track your usage and sell that information to anyone who wants to track you. While all VPN providers deny they do this, several have been caught doing so. Avast, for example, has paid multimillions of dollars in fines for doing it repeatedly, after court settlements where they denied it. And even if your VPN provider is “honest”, it can be hacked, as NordVPN was recently.

Knowing this, if you still want to be less secure by using VPN go ahead and reinstall it. The problem you are most likely having is explained here: An important and frequently overlooked fact is that when you install VPN it configures itself to the specific hardware, OS version and network that the device uses. If any of those change it can break the VPN. So any time you change any of these you may need to delete the VPN app and profile, restart your device, then add them back (if you still want to use VPN) so it can configure itself to the new environment.

Here's more detail about: VPN - What you need to know

Had the same issues as OP, waited 3-5 days for the indexing to finish and still have some lags, but what worked was, I went on Setting - Accessibility - Display & Text Size - Reduce Transparency,

Turning it off, quiting setting, and then turning it on again, seems to make the phone run better. Everything is snappy again. Maybe it’ll work for you too.

I’m on iphone 13 128gb with 24gb of storage left.

I found that closing all apps after updating significantly reduces/eliminates lag.

To me, it seems like performance suffers when using an app that has remained open since pre-update. Closing and reopening an app after updating allows the app to factor in your current iOS version. After doing this once, you can continue using your lagfree updated phone as you normally would.

For information; I’m using an iPhone 14 Pro 512GB with ~380GB of unused storage running iOS 26.1 (23B85). My battery condition is currently at 81%, and it’s been ~12 hours since updating from iOS 18.6. I did not adjust any settings, including settings related to Apple Intelligence.

Two things:

• Let us know when you updated.
• Post the screen shot you see at Settings > Battery, that shows the green battery graph with the last 24 hour option and the top apps using the battery.

For the early adopters who updated last Monday, the indexing has already completed and the reports about battery drain, heat, and lag have dropped significantly.

About Apple software updates - Apple Support

SOLUTION- I was having same problem and I know the solution might sound super basic but:

I went to the app store and hit the update button and updated all the apps.. the phone magically stopped lagging . I know, crazy😅

The latest patch iOS 26.0.1 has partially solved the problem for my iPhone 12. Now the APPs don't crash, and the phone has minimized the absolutely laggy behaviour of iOS 26. Still lags, but at least the phone can be used.

Folks, I think I figured it out. TURN OFF LOW POWER MODE

mainly I was experiencing micro lag. I’ve done everything from reduce transparency, update all apps, turn on and off phone - but the solve was to turn off low power mode.

hope this helps

I have an iPhone 15 Pro. I tried reducing Transparency in Accessibility. I tried removing my VPN profile. These did not work.

What worked was turning off Apple Intelligence. As soon as I turned it off my phone lag was gone.

Hope this works for you.

I used apple support which was very helpful. It took a while but what finally fixed it was to delete VPN apps on iphone 13

While this is apparently resolved, what does Apple suggest for VPN if on public wifi?

iPhone 14Pro here on iOS 26.1, 256GB.

Go to Settings > Search.

Turn off “Help Apple improve search”.

It changed a lot for me, phone is usable again. I guess it must have been setting up some encrypted connection with Apple servers every time search was available (any browser address input, in many apps etc). Before the change I practically couldn’t use safari. Now it’s smooth.

Toggling off reduce transparency work for my 15 pro max, cheers!

Perhaps a long shot:

Do you have a 3rd party VPN installed, even if you are not using it? If so, delete the VPN profile in Settings/General/VPN & Device Management/VPN, then restart your device. Don't just turn it off; delete the profile. If that fixes it, you can try reinstalling VPN, but probably shouldn't.

(VPN isn’t the cause of all problems, but it is responsible for a great many)

Was having the same issues. Terrible lag specially affecting my keyboard. Disabling and disabling vpn solved it