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# systemPrefersReducedResourceUsageDidChangeNotification

A notification that posts when [`systemPrefersReducedResourceUsage`](/documentation/UIKit/UIApplication/systemPrefersReducedResourceUsage) changes.

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

## 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.

---

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