July 23, 2026, 7:43 am | Read time: 3 minutes
After every major iOS update, users complain that their iPhones run slower, heat up faster, and the battery drains quickly. This is completely normal, as new features often require an initial assessment where existing data is re-indexed. This process should typically take no more than a few hours, occasionally up to a full day. However, iOS 27 introduces such extensive changes that beta testers currently have to wait several days for the update to complete.
iPhone Builds New Search Index
At the WWDC 2026, Apple announced a series of performance improvements for iOS 27. Special attention was given to Spotlight Search–the integrated iPhone search function that can scour files, websites, app content, messages, emails, and more. According to the keynote, the “technical foundation of the search” has been completely redeveloped.
Spotlight is based on the search index, a catalog that the iPhone creates with all content and their storage locations. With the update to iOS 27, Apple’s new search infrastructure re-indexes all content on the device to make the search more reliable, efficient, and comprehensive–for both old and new content.
iOS 26.6 Is Here! Should You Install the Update Right Away?
Apple Confirms Shorter Battery Life Due to iOS 26
Users Report Weeks-Long Wait Times
After installing iOS 27, a pop-up window with the message “Indexing in Progress” appears. Users can continue to use the device during this time. The re-indexing process should typically take a few hours to a few days. However, users on Reddit report that the process is still not complete weeks after installing the iOS 27 beta is still not complete. For some, the indexing seems to stall at 94 or 95 percent.
According to Apple analysts from “Tech Between the Lines,” the duration depends on the amount of data, the number of email accounts, and the device’s performance. iPhones with many photos, long message threads, and extensive email archives require more time.
Apple offers a tip to speed up the process: “Longer charging sessions help accelerate indexing.” The reason is that the iPhone slows down or completely halts the process when the battery is low–similar to cloud synchronization in the Photos app. Indexing runs fastest when the iPhone is charging, connected to Wi-Fi, and not in use.
Also interesting: iOS 27 Beta 4 gives new hint about foldable iPhone
Renew Search Index in Advance
As long as the index is incomplete, the search can deliver incomplete results according to “Tech Between the Lines.” Even familiar terms may not appear in the settings search. While the process is ongoing, the battery may drain faster, and the iPhone may heat up more than usual.
Users will soon be able to start the re-indexing process in advance to ease their devices during the future update to iOS 27. Apple is expected to release iOS 26.6 shortly. The update “optimizes the Spotlight index to prepare for iOS 27,” as stated in the release notes.