Apple’s iOS 27 introduces an aggressive local indexing system for Search and Siri, building a private on-device index of apps, messages, email, contacts, photos, notes, music, settings and more to speed up results.

The indexing is designed to keep information locally on the device, enabling up-to-date Spotlight search and an upgraded Siri experience without sending the index to Apple.

During the iOS 27 update, the system triggers a banner and begins reindexing existing data on the iPhone to support the overhaul.

The banner should disappear once indexing finishes, with any warmer device temperature or altered battery life explained by background indexing activity.

There is no fixed completion time for indexing; it can take hours or days depending on data volume, and the iPhone remains usable during the process.

Search results may be incomplete until indexing is complete, but users can continue to use the iPhone during the process.

If Spotlight isn’t functioning after indexing, review per-app Spotlight permissions in Settings > Search to ensure correct access.

If the message lingers beyond a reasonable period, ensure the device has the latest software and reference Apple support guidance on Spotlight indexing after updates.

Indexing may take from several hours to multiple days, especially with larger storage and a full rebuild of the new search system in iOS 27.

To speed things up, keep the device on power, connected to Wi‑Fi, and minimize active use; best results come from normal device use while indexing runs in the background.

Apple’s guidance emphasizes keeping the device charged and on Wi‑Fi while indexing proceeds, with users able to use the device in the background.

Indexing begins after setup, software updates, or upgrades and may appear soon after updating to iOS 27.