Many iPhone 18 Pro users who recently updated iOS are reporting serious performance issues — laggy animations, slow unlocking, delayed touch response, and general sluggishness across the system. You’re not imagining it — this seems to be a widespread problem.
The issue:
- iPhones feel noticeably slower and choppier after the update.
- Animations stutter when swiping, opening Control Center, or pulling down Notification Center.
- Face ID and screen unlocking take a few seconds longer than before.
- Apps — especially Safari, Camera, and Messages — lag or flicker when launching.
- Battery drains faster, and some devices even overheat during light use.
- Low Power Mode makes things even worse for some.
Why this may occur:
- Background Indexing: After a major update, your iPhone re-indexes Spotlight search, Messages, and Photos (for visual recognition). This process can make your device run hot and feel sluggish for 1–3 days.
- Apple Intelligence Integration: The new AI-based features rely on background data preparation. Even if you don’t actively use them, they can temporarily increase CPU load.
- Liquid Glass UI Effects: The redesigned “Liquid Glass” visuals demand more from the GPU. Users with older or even current-gen models say these effects introduce micro-stutters.
- Low Power and Adaptive Modes: Ironically, enabling these modes can throttle the phone too aggressively, reducing frame rates and responsiveness.
- Storage and Heat: Devices with little free space (less than 15–20%) tend to perform worse because background tasks can’t complete properly.
How to fix
- Wait for indexing to finish: Leave your iPhone plugged in and on Wi-Fi overnight for a couple of days. Many users reported smoother performance after 48–72 hours.
- Turn off Low Power Mode: Go to Settings > Battery > Power Mode > Low Power Mode > turn it off.
- Free up storage: Make sure at least 10–15 GB of space is available. Go to Settings > General > iPhone Storage to review large apps and videos. You may also consider buying additional iCloud storage, especially if your iPhone is running low on free space — limited storage can slow down indexing and system performance after major updates, like this one.
- Reduce Transparency & Motion: Tap Settings > Accessibility > Display & Text Size > Reduce Transparency > ON. And then go to Settings > Accessibility > Motion > Reduce Motion > ON and enable Prefer Cross-Fade Transitions.
- Restart or Force Restart your iPhone 18 Pro: Press Volume Up and Volume Down and then hold the Side button until the Apple logo appears.
- Reset All Settings (without erasing data): Go to Settings > General > Transfer or Reset iPhone > Reset > Reset All Settings: Doing so will reset all system preferences to their defaults without deleting your personal data like photos, apps, or messages.
- Update all apps from the App Store: Some third-party apps may perform poorly until updated.
- Disable unnecessary VPN profiles: Several users noted lag improved after removing old VPN or configuration profiles.
