Sorry, this type of
URL
scheme
(undefined
) is not
supported by this service. Please check that you entered the URL correctly.
URLs should be in the form: https://validator.w3.org/
If you entered a valid URL using a scheme that we should support, please let us know as outlined on our Feedback page. Make sure to include the specific URL you would like us to support, and if possible provide a reference to the relevant standards document describing the URL scheme in question.
Remember that you can always save the page to disk and Validate it using the File Upload interface.