Validator.nu Textarea Input
To use Validator.nu as a Web service by POSTing a text field, the client issues an HTTP request either to
http://html5.validator.nu/ using the POST method with an
multipart/form-data entity body. (
application/x-www-form-urlencoded is not supported.) Common parameters are encoded as form fields and must decode as UTF-8. The document to check is included as the value of a form field called
content field must be the last field in the submission.