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Refli
User level: Level 1 (6 points)

Very poor performance from Iphone Air!

After updating my device to iOS 27, I have been experiencing significant lag across multiple apps and even within the system settings. The overall performance has noticeably decreased, making the device feel slow and unresponsive.


I would like to know whether this is a known issue with iOS 27 and whether there are any recommended steps to improve the performance.


I am also experiencing very poor battery life. My phone cannot last even half a day with normal use. I get a maximum of around 3 hours of screen-on time before the battery drops from 100% to approximately 20%.


I recently purchased the MagSafe Battery for the iPhone Air, but even with the additional battery, I still cannot get through a full day of use.


My device is an iPhone Air. The battery health is currently at 96%, with approximately 240 charge cycles.


Considering the relatively high battery health, I would not expect the battery life to be this poor. I would appreciate any guidance on whether this could be related to iOS 27 or whether there may be another issue affecting the device.

Posted on Sep 21, 2026 2:28 PM

3 replies

Mac Jim ID
User level: Level 10 (105,996 points)

Sep 21, 2026 2:41 PM in response to Refli

After every update, you should expect background processes to run in the background and normally that continues for about 4 days. With iOS 27, there is additional Search & Siri Optimizations being performed, so you could expect it to be a bit longer to let those complete. After every update during this indexing, you should expect to see:

  • Increased Battery Drain
  • Increased Heat from the device
  • Increased UI lag

About Apple software updates - Apple Support


So the biggest question is, when did you update to iOS 27?

Jeff Donald
User level: Level 9 (64,078 points)

Sep 21, 2026 2:44 PM in response to Refli

What does your iPhone Air display for time required to finish syncing? Look in your settings app. A delay in performance is expected behavior for up to a week beyond upgrading your device.


Apple does not disclose known issues. This community is a user to user community. In other words I’m just like, but I’ve been here for over 25 years and perhaps have a better way of extremely challenges you’re facing.


If you want a fellow user to help diagnose the issue, I’m happy to do so. But I just want to set the proper expectations. If you want official Apple Support, here is the information.


If you’re in the US, please call  1-800-MY-APPLE, or outside the US, consult the support articles below. In Canada, call 1-800-263-3394.


Contact Apple for support and service - Apple Support


Genius Bar Reservation and Apple Support Options - Apple

LordVardwar
User level: Level 1 (8 points)

Sep 24, 2026 6:44 AM in response to Refli

Same issues. iPhone Air is brand new. My iPhone 14 Pro was perfect on iOS 26. It’s been over a week, no indexing anymore. Laggy UI across all apps, mostly apple apps. Delayed keyboard showing, slower FaceID. My phone battery is 100% health. Not indexing spotlight.

Originally posted at discussions.apple.com/thread/256362225