I found another solution. If you use Swift, you can set encoding with .isoLatin1 // codes let data = Data(base64Encoded: profileContent) let outputStr = String(data: data!, encoding: .isoLatin1) try outputStr?.write(to: saveUrl, atomically: true, encoding: .isoLatin1) it works fine in my application~

From security considerations, you should not connect to the remote database directly in the application.  If you are only locally stored, you can consider using a cross-platform RealmSwift.