HTML Checking for Large Sites

Rocket Validator automatically checks your pages on the W3C Validator.

Bad value X for attribute “srcset” on element “source”: No width specified for image Y. (When the “sizes” attribute is present, all image candidate strings must specify a width.)

The sizes attribute is used to complement the srcset attribute on an <img> tag for responsive images. When this attribute is present, all image candidates must specify its width.

Learn more:

25,000 HTML checks per month. Is that enough for your site?

Save time using our automated web checker. Let our crawler check your web pages on the W3C Validator.