# download(resumeFrom:delegate:) Resumes a previously-paused download and delivers the URL of the saved file asynchronously. ``` func download(resumeFrom resumeData: Data, delegate: (any URLSessionTaskDelegate)? = nil) async throws -> (URL, URLResponse) ``` ## Parameters `resumeData` A data object that provides the data necessary to resume a download. `delegate` A delegate that receives life cycle and authentication challenge callbacks as the transfer progresses. ## Return Value An asynchronously-delivered tuple that contains the location of the downloaded file as a URL, and a [`URLResponse`](/documentation/Foundation/URLResponse). ## Discussion Your app can obtain a `resumeData` object in two ways: - If your app cancels an existing transfer by calling [`cancel(byProducingResumeData:)`](/documentation/Foundation/URLSessionDownloadTask/cancel(byProducingResumeData:)), the session object passes a `resumeData` object to the completion handler that you provided in that call. - If a transfer fails, the session object provides an `NSError` object either to its delegate or to the task’s completion handler. In that object, the [`NSURLSessionDownloadTaskResumeData`](/documentation/Foundation/NSURLSessionDownloadTaskResumeData) key in the `userInfo` dictionary contains a `resumeData` object. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)