What field would I use for an external URL?

Please can someone indicate what field I would use for a URL. i.e I want to display www.google.co.uk but which links to https://www.google.co.uk do i create two separate text fields or is there an easier way.
Two fields is not very efficient from a data inputting perspective or to user who is just an editor.

I’d go for a regular textfield and use the options to define a pattern, or use an external PHP file to use a regular expression to validate initially, maybe even a bit of cURL magic to get the header for a URI and see if it returns a valid HTTP header.