my iphone 6s is running very slow after ios 11.0.3

Sounds as though it might be time to get the battery checked out and possibly replaced.

My 5s started running slower and doing random shut-downs, even with a full charge. It began doing these after the iOS 10 update, but since I'd had the phone for for 3 years by then, and it's my only phone for the past 2 years, I figured it was time to get clarity on why this was happening, as it was only getting worse with each update. It was driving me bonkers when traveling and needed Google Maps to guide me (btw, I'm still using iOS 10.3.3) and other apps to help find flight info, restaurants, etc.. I finally took my iPhone to my local Apple store in June of this year.

The tech I saw ran a diagnostic on my phone. One of the diagnostics showed how many charging cycles I'd done and that I only had 63% of battery usefulness/capacity left, even when fully charged... something I couldn't see myself to know that was the problem. The tech said I could either buy a new iPhone (I'm still considering buying an SE for several reasons, but haven't the cash right now) or replace the battery. The battery replacement would be $79 + sales tax and the Apple store could do it right then and there. I decided to investigate it a bit at home and learned an indy shop would likely charge about half what Apple does. So, I called 4 indy repair shops. The shop I went with charged me $32 + sales tax. The most expensive indy shop wanted $48 + sales tax. I could have bought all the necessary parts on Ebay and done it myself, but I was too worried of causing damage to my phone, because my eyesight isn't that great anymore. So, for the extra $10 or $20 dollars I paid, I figured it was worth sitting in the indy shop's waiting room for an hour (I actually went for a walk instead since it was gorgeous day) and letting someone more skilled than I do it for me. SO worth it! Having a new battery totally solved the slowness and random shut-down issues I was experiencing.

I haven't updated to iOS 11.x because I haven't got enough room in my iCloud storage account, and I can't afford to be without a phone, in case I run into any problems.

I also run a VPN on my phone to prevent snooping, etc. too. Yes, it eats up battery charge when it's running, but replacing the battery is much cheaper than buying a new phone.

Here’s a FIX that someone from another thread suggested and it has worked for me.

Go to Settings, Reset, and select RESET ALL SETTINGS.

This does not wipe or erase any data on your phone but it does erase all of your phone settings such as WiFi, Notifications Settings for each app, passcode, fingerprint, wallpaper etc. So mainly the phone function settings only. Stuff like email, apps data, contacts and all the data oriented stuff will still be there.

But you should definitely do a backup before you reset.

All in all, it took about 30 mins from the time I pressed RESET ALL SETTINGS to the time I had to go enter in all of my original phone settings. But my phone seems to be working as fast as it was before the IOS 11.0 upgrade...thank goodness!

Good luck all!

The possibility of battery issues/degradation being responsible for iOS 11 issues on iPhone 6/6S models has been mentioned here and another iPhone 6/6S thread.

Some users have already got their iPhone 6/6S battery replaced and those users reported that iOS 11 is now workng fine for them.

You CAN have the battery replaced in iDevices.

This is NOT planned obsolescence, at all.

https://www.apple.com/batteries/service-and-recycling/

To everyone here.

Apple design/software teams and engineers do not read these forums.

Apple supplies these forums for users to work out their product issues with other users, but these community forums ARE monitored/moderated by Apple Staff assigned to these community forums, but I do not think any info is ever passed on to who/mever the cognizant parties are who would need to know if there are any mounting issues with a product or software.

The only way to get Apple to listen to you is to use their feedback portion of their website.

There is a small, but growing minority of iPhone 6/6S users that have been experiencing less than normal or stellar performance on any version of iOS 11.

Has anyone here tried any of these as a possible fix or improvement?

Have any of you tried a hard reset of your iPhone 6/6S by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons?

Make sure your iPhone 6/6S has and maintains , at the very least, 3-4 GBs of free data storage space!

In Settings app, General settings panel, turn OFF Background App Refresh.

In Settings app, under General settings, Reset panel, at the right bottom of the list, Reset All Settings.

In Settings app (NOT from the iOS Control Panel) turn OFF Bluetooth when not using any Bluetooth devices.

Also, in general, if you want a faster IDevice, on all of my iDevices, I turn off most of the iOS motion graphics eye candy, by simply turning ON Reduce Motion in Settings app, General, Accessibilty settings.

If none of this, so far, has helped your iPhone 6,/6S,

What about doing a complete backup to iCloud or iTunes on a computer, then do a complete erase and reset as new in the Settings app under General, Reset then restore your backup from iCloud or iTunes?

If still no joy after the erase and restore, hammer Apple with constant feedback about the iPhone 6/6S issues here.

iPhone Feedback

http://www.apple.com/feedback/iphone.html

This is THE ONLY avenue to get Apple’s DIRECT attention to any and all iPhone 6 issues!

IF no one posts feedback about iPhone 6/6S issues, Apple will NEVER know there is an issue and will never correct it!

Cognizant Apple employees read ALL feedback generated from all of the various feedback pages and transfers the data to the appropriate Apple personnel , but NO Apple employees will ever respond with any type of direct, individual replies from the feedback you post.

Good Luck to You All!

Adding to the reply string. Same problems as others. Tried hard reboot. Tried removing and reinstalling multiple apps. I've scheduled an appointment with my local Apple Store. Fingers crossed.

Update from Apple Chat. Diagnostic discovered I've exceeded the number of battery recharges - limit is apparently 500 before the iPhone battery starts to degrade below 80%. (Wow, that was a shocker). And they acknowledged that iOS will get corrupted - only solution is to run a backup and do a complete refresh through iTunes.

Never had these issues with my 4, or 5 which I've passed onto my kid. #designedinobsolescence.

I turned off Hey Siri and Siri Search and Suggestions and my phone is now usable again. I also turned on Reduce Motion under Accessibility. I think the Siri fix was what made the difference however.

They released a 11.1 patch.

I performed ‘reset settings’ then restored from backup, and it has made a difference. My 6S had been dog slow and laggy after updating to 11.0.3. It’s much more responsive after the restore (but not 100% cured).

I'm having the same problem too. It's because iOS 11.0.3 is still not a stable version. It is just a temporary remedy to some iPhone 8 and iPhone 7 users. That's why Apple has worked on the iOS 11.1 so well, it's now a little more stable than the previous iOS versions and we are all expecting a better, faster and more stable iOS in the upcoming iOS 11.2 which is currently on beta testing. iOS 11 will become great as long as Apple don't stop developing it.

Reset helped. I brought the phone into an Apple Authorised service centre to have them do it. So I can finally type this message to you. But it solved 60% of the problem. The phone still hangs for no reason. This is reaaly frustration when you have an urgent call or message.

Agree that battery needs to be replaced at some point, however, getting a new battery on your iPhone 6 will not solve slow response that is a function of IOS 11. I know. I got a new Apple OEM battery (60.00). My phone is still not like it used to be on IOS 10. I hate what IOS 11 has done to my performance. I type a text and the letters trail behind.

Hi

When an iphone it 2/3 years Old it will need a new battery

Go to apps store download Battery life it will test your battery condition.

Cheers

Brian 🇬-1F1E7;

Apple's ios 11.0.3 update is totally disastrous for my iPhone 6s.

1. Like most on the thread, my phone performance is so shocking it is rendering my phone almost useless. I can barely use it. I have reverted to an older iPhone i have with an old ios just to get by.

2. Since the ios 11.0.3 update my battery life on my phone is exceedingly bad. I can actually see my battery life decrease as it is used.

Apple needs to be very quickly provide a property a patch update with proper testing done to ensure it is stable.