# appendingPathComponent(_:conformingTo:) Returns a URL by appending the specified path component with the file extension for a uniform type identifier. ``` func appendingPathComponent(_ partialName: String, conformingTo contentType: UTType) -> URL ``` ## Parameters `partialName` The partial name to append. `contentType` A uniform type identifier the resulting conforms to. ## Return Value A new URL with the partial name and the type’s preferred extension appended. ## Discussion Use this method when you want to mix partial input from a user or other source, and need to produce a complete filename suitable for that input. For example, if you download a file from the internet and know its MIME type, you can use this method to ensure the URL has the correct filename extension where you save the file. If `partialName` already has a path extension, and that path extension is valid for file system objects of type `contentType`, the function doesn’t add an extension before appending it to the URL. For example, if the inputs are `puppy.jpg` and , respectively, the function returns a URL with an appended path component of `puppy.jpg`. However, if the inputs are `puppy.jpg` and , respectively, the function returns a URL with an appended path component of `puppy.jpg.txt`. If you want to replace any existing path extension, use the [`deletePathExtension()`](/documentation/Foundation/URL/deletePathExtension()) method first. If the function can’t append the path component, it returns an unchanged URL. > Note: > The modified URL has a directory path if `contentType` conforms to . For more information about types, see . --- 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)