Validator.nu Form Upload Input

To use Validator.nu as a Web service by form-based file upload:

• the client issues an HTTP request either to https://validator.nu/ or https://html5.validator.nu/

• the request uses the POST method with an multipart/form-data entity body

• common parameters are encoded as form fields

• the document to check is included as the value of a file upload field called file

• the file field must be the last field in the submission

Since the Content-Type supplied by browsers for the uploaded file is unreliable, the client-supplied Content-Type is overridden with a synthetic Content-Type if the filename is supplied and it has a well-known extension. The well-known extensions are html, htm, xhtml, xht, atom, rng, xsl, xml and dbk.

The parameter field values must decode as UTF-8.

See also

• Validator.nu Web Service Interface