---
title: URLError
framework: foundation
role: symbol
role_heading: Structure
path: foundation/urlerror
---

# URLError

Error codes returned by URL loading APIs.

## Declaration

```swift
struct URLError
```

## Mentioned in

Pausing and resuming uploads

## Overview

Overview These error codes are for NSError objects in the domain NSURLErrorDomain.

## Topics

### Error details

- [failingURL](foundation/urlerror/failingurl.md)
- [failureURLPeerTrust](foundation/urlerror/failureurlpeertrust.md)
- [failureURLString](foundation/urlerror/failureurlstring.md)
- [downloadTaskResumeData](foundation/urlerror/downloadtaskresumedata.md)
- [backgroundTaskCancelledReason](foundation/urlerror/backgroundtaskcancelledreason-swift.property.md)
- [URLError.BackgroundTaskCancelledReason](foundation/urlerror/backgroundtaskcancelledreason-swift.enum.md)
- [networkUnavailableReason](foundation/urlerror/networkunavailablereason-swift.property.md)
- [URLError.NetworkUnavailableReason](foundation/urlerror/networkunavailablereason-swift.enum.md)

### Error codes

- [appTransportSecurityRequiresSecureConnection](foundation/urlerror/apptransportsecurityrequiressecureconnection.md)
- [backgroundSessionInUseByAnotherProcess](foundation/urlerror/backgroundsessioninusebyanotherprocess.md)
- [backgroundSessionRequiresSharedContainer](foundation/urlerror/backgroundsessionrequiressharedcontainer.md)
- [backgroundSessionWasDisconnected](foundation/urlerror/backgroundsessionwasdisconnected.md)
- [badServerResponse](foundation/urlerror/badserverresponse.md)
- [badURL](foundation/urlerror/badurl.md)
- [callIsActive](foundation/urlerror/callisactive.md)
- [cancelled](foundation/urlerror/cancelled.md)
- [cannotCloseFile](foundation/urlerror/cannotclosefile.md)
- [cannotConnectToHost](foundation/urlerror/cannotconnecttohost.md)
- [cannotCreateFile](foundation/urlerror/cannotcreatefile.md)
- [cannotDecodeContentData](foundation/urlerror/cannotdecodecontentdata.md)
- [cannotDecodeRawData](foundation/urlerror/cannotdecoderawdata.md)
- [cannotFindHost](foundation/urlerror/cannotfindhost.md)
- [cannotLoadFromNetwork](foundation/urlerror/cannotloadfromnetwork.md)
- [cannotMoveFile](foundation/urlerror/cannotmovefile.md)
- [cannotOpenFile](foundation/urlerror/cannotopenfile.md)
- [cannotParseResponse](foundation/urlerror/cannotparseresponse.md)
- [cannotRemoveFile](foundation/urlerror/cannotremovefile.md)
- [cannotWriteToFile](foundation/urlerror/cannotwritetofile.md)
- [clientCertificateRejected](foundation/urlerror/clientcertificaterejected.md)
- [clientCertificateRequired](foundation/urlerror/clientcertificaterequired.md)
- [dataLengthExceedsMaximum](foundation/urlerror/datalengthexceedsmaximum.md)
- [dataNotAllowed](foundation/urlerror/datanotallowed.md)
- [dnsLookupFailed](foundation/urlerror/dnslookupfailed.md)
- [downloadDecodingFailedMidStream](foundation/urlerror/downloaddecodingfailedmidstream.md)
- [downloadDecodingFailedToComplete](foundation/urlerror/downloaddecodingfailedtocomplete.md)
- [fileDoesNotExist](foundation/urlerror/filedoesnotexist.md)
- [fileIsDirectory](foundation/urlerror/fileisdirectory.md)
- [httpTooManyRedirects](foundation/urlerror/httptoomanyredirects.md)
- [internationalRoamingOff](foundation/urlerror/internationalroamingoff.md)
- [networkConnectionLost](foundation/urlerror/networkconnectionlost.md)
- [noPermissionsToReadFile](foundation/urlerror/nopermissionstoreadfile.md)
- [notConnectedToInternet](foundation/urlerror/notconnectedtointernet.md)
- [redirectToNonExistentLocation](foundation/urlerror/redirecttononexistentlocation.md)
- [requestBodyStreamExhausted](foundation/urlerror/requestbodystreamexhausted.md)
- [resourceUnavailable](foundation/urlerror/resourceunavailable.md)
- [serverCertificateHasBadDate](foundation/urlerror/servercertificatehasbaddate.md)
- [serverCertificateHasUnknownRoot](foundation/urlerror/servercertificatehasunknownroot.md)
- [serverCertificateNotYetValid](foundation/urlerror/servercertificatenotyetvalid.md)
- [serverCertificateUntrusted](foundation/urlerror/servercertificateuntrusted.md)
- [secureConnectionFailed](foundation/urlerror/secureconnectionfailed.md)
- [timedOut](foundation/urlerror/timedout.md)
- [unknown](foundation/urlerror/unknown.md)
- [unsupportedURL](foundation/urlerror/unsupportedurl.md)
- [userAuthenticationRequired](foundation/urlerror/userauthenticationrequired.md)
- [userCancelledAuthentication](foundation/urlerror/usercancelledauthentication.md)
- [zeroByteResource](foundation/urlerror/zerobyteresource.md)
- [URLError.Code](foundation/urlerror/code.md)

### Instance Properties

- [uploadTaskResumeData](foundation/urlerror/uploadtaskresumedata.md)

## Relationships

### Conforms To

- [CustomNSError](foundation/customnserror.md)
- [Equatable](swift/equatable.md)
- [Error](swift/error.md)
- [Hashable](swift/hashable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Errors

- [URL Loading System error info keys](foundation/url-loading-system-error-info-keys.md)