IOS 27 optimizing stuck at 43%

If the 43% you’re seeing is the Search/Siri “Optimizing” progress after the update, that process can take quite a while. Apple says indexing after a software update can take hours or even days depending on how much data is on the iPhone. → About Spotlight indexing and search results on Apple devices - Apple Support

I’d leave the iPhone connected to power and Wi-Fi overnight, preferably while you’re not using it. That gives the indexing process the best chance to finish.

If it’s still sitting at exactly 43% after another day, restart the iPhone and check for any newer iOS 27 update under Settings > General > Software Update.

If you mean a different “Optimizing” screen, let us know where you see the 43% and we can narrow it down.

Shourav993 wrote:

It’s been 4 days and it still stuck on 35%. Though it showed me 49% after 1 day but after that it came down to 35% and still now at 35%. I tried everything apple said bit same problem, stuck at 35%.

I see from your screenshot that the phone is not plugged in and not connected to WiFi. Plug it in before you go to bed. Make sure it's connected to WiFi.

[Edited by Moderator]

philipblair wrote:

https://discussions.apple.com/content/attachment/d8b6fca7-d0e6-4b57-bd82-d1569bba3ac2

Thank you for posting the screenshot.

You'll see this notification appear in the settings sidebar after updating to iOS/iPadOS 27 - this indicating that (a) the expected reindexing process is running, and (b) you should anticipate impacted system performance while this background process continues to run. I remain curious, however, where you are seeing the 43% progress that you report with the title of your post.

Speaking of personal experience with both iPhone and iPad with iOS/iPadOS 27, the reindexing process continued for 36-48hrs - after which the settings sidebar notification disappeared and system performance dramatically improved.

As recommended by Apple, the indexing process can be hastened by leaving the device locked and connected to its Power Adapter while this process is running. Should you need to use the device, you can do so at the expense of indexing taking longer.

Hi, iOS 27.2 was released three days ago. Please update your iPhone and give it 5 to 7 days to finish indexing, syncing and optimizing. During that time your device may occasionally seem slow or sluggish. This is due to the CPU and GPU doing the above processing. Higher than normal battery usage and higher temperatures may also be observed. You can minimize your inconvenience by plugging your device into a charger, connecting to WiFi and locking it before you go to bed. This allows the device to complete tasks while you’re sleeping and minimize your daytime downtime. Good luck.

I went thru the steps I found online to do a hard restart. Then plugged into power, made sure connected to WiFi, and let it sit for 10 hours.

That finally fixed it

Have you done a forced restart? This may have resolve the current stalling of the optimization.

Force restart iPhone - Apple Support

For me, it took slightly over 2 full days with the phone plugged into power and connected to WiFi for about 30 hours during that time. I no longer see the message in Settings saying the optimizations are being performed. I don't see where Apple would be able to speed up the process.

From the message, it seems apparent the time it takes would vary individually based not only on how much time the device has to index when not in use, but also the amount of data that it needs to index. When you tap Learn More, it says it could take hours or days depending on those factors and I would not recommend toggling Siri in case that would start over rebuilding the Spotlight index.

Search optimization only happens when the phone is idle. And take PreCognition’s advice on connecting to power and Wi-Fi.

Where, precisely, are you seeing this "optimising" reported?

Posting a screenshot here may be helpful - as this will help contributors here to properly understand precisely what you see - and then provide appropriate guidance without having to guess the nature of the problem.

Take a screenshot on iPhone - Apple Support

You can upload your screenshot (suitably redacted using markup tools to obscure any personal or sensitive information) using the image button found at the bottom of the message editing window:

Apple specifies WiFi. How many bars do you have with AT&T? Are you on 5G+? Make sure you’re not in Low Data mode. Make sure you have iCloud Drive and iCloud backup enabled.

After a week of getting stuck at 34%, mine is ok now. What i did differently is I turned off power saving mode (not sure if that did anything).

I think it is possible that there’s a bug in showing percentages while actually it was running fine in the background.

I’ve tried turning search off, Siri off, forced resets and even network reset all to no avail (suggestions for fixes in Google).

The only thing in haven’t done is to de a complete reset and restore to factory settings, which I wasn’t willing to do this morning but as nothing at all is changing I am getting tempted to factory reset.

My wife installed the update 24+ hours after I did it and hers completed the optimisation in about six hours.

I updated to ios27 Monday 16P. My phone has been connected to WiFi and charging overnight for 4 days. Still sitting at 35 percent complete. I have tried two force restarts and a regular shutdown, but it’s still stuck.

It’s been 4 days and it still stuck on 35%. Though it showed me 49% after 1 day but after that it came down to 35% and still now at 35%. I tried everything apple said bit same problem, stuck at 35%.

[Edited by Moderator]