---
title: systemPrefersReducedResourceUsageDidChangeNotification
framework: uikit
role: symbol
role_heading: Type Property
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, tvOS 27.0+, visionOS 27.0+]
path: uikit/uiapplication/systemprefersreducedresourceusagedidchangenotification
---

# systemPrefersReducedResourceUsageDidChangeNotification

A notification that posts when systemPrefersReducedResourceUsage changes.

## Declaration

```swift
nonisolated class let systemPrefersReducedResourceUsageDidChangeNotification: NSNotification.Name
```

## Discussion

Discussion The object of the notification is the UIApplication object. The userInfo dictionary is empty. Re-read systemPrefersReducedResourceUsage to get the new value. Use this notification to re-read the value and adjust the scheduling of future work, the same way the property is read proactively. Avoid performing or scheduling expensive work directly in the handler, as this could worsen resource usage.