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# isConstrained

A Boolean value that indicates whether the connection operates over an interface marked as constrained.

```
var isConstrained: Bool { get }
```

## Discussion

A constrained interface is one the user marks as constrained by selecting “Low Data Mode” in the Settings app. You permit or deny use of constrained interfaces with the [`allowsConstrainedNetworkAccess`](/documentation/Foundation/URLSessionConfiguration/allowsConstrainedNetworkAccess) property on [`URLSessionConfiguration`](/documentation/Foundation/URLSessionConfiguration) or [`allowsConstrainedNetworkAccess`](/documentation/Foundation/URLRequest/allowsConstrainedNetworkAccess) on [`URLRequest`](/documentation/Foundation/URLRequest).

---

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