But robnotyou, I'm looking for a BIG win! 😁 Thanks so much for the quick response! It might upset my already-tuned settings, but I'll try it out.

In the example below for Swift users, "UTType.mpeg4Movie" replaces "kUTTypeMPEG4" The dev group did a nice job cleaning up the syntax. The dev docs group dropped the ball by noting that that "typeIdentifierKey" is deprecated, but not mentioning that "contentTypeKey" is the intended replacement - https://developer.apple.com/documentation/foundation/urlresourcekey/1416354-typeidentifierkey. The "contentTypeKey" could refer to anything; "contentTypeIdentifierKey" or "contentUTIdentiferKey" would have made it several hours easier to figure out. Note: the example extension of URL maybe applies solely to macOS and/or file URLs. Advance apologies for typos. Sample usage for casual hobbyists like me: let myFileURL = URL( ... appropriate initialization here ...) // unwrap as needed if myFileURL.isMPEG4{ //do stuff } Extension: extension URL { // new style var contentType: UTType? { return (try? resourceValues(forKeys: [.contentTypeKey]))?.contentType } var isMPEG4:Bool { guard let contentType = contentType else {return false} // search for contentType failed return contentType.conforms(to: UTType.mpeg4Movie) ? true : false } // this is deprecated (macOS > 12?) // based on: https://stackoverflow.com/questions/28570627/how-to-find-file-uti-for-file-withouth-pathextension-in-a-path-in-swift var typeIdentifier: String? { return (try? resourceValues(forKeys: [.typeIdentifierKey]))?.typeIdentifier // will need to convert output to CFString to test against UTTypeConformsTo } var DeprecatedIsMPEG4:Bool { guard let typeIdentifier = typeIdentifier else {return false} // test against the specific type if UTTypeConformsTo(typeIdentifier as CFString, kUTTypeMPEG4) {return true} return false } }