I am in the middle of struggling with Swift6 and facing the same compile error, too. URLSession methods demand @Sendable in their closures. How about using Kingfisher's downloder? import Kingfisher ... let downloader = ImageDownloader.default downloader.downloadImage(with: url) { result in switch result { case .success(let value): //value.originalData is Data ... contentHandler(bestAttemptContent) case .failure(_): contentHandler(bestAttemptContent) } } ... or using NSData.init?(contentsOf url: URL) (This runs synchronously, not an ideal solution but very simple one) https://developer.apple.com/documentation/foundation/nsdata/1413892-init At least, this compile error vanishes with any of these. (Currently we have too many compile errors with Swift6.)