HTML Checking for Large Sites
Rocket Validator automatically checks your pages on the W3C Validator.
HTML issues tagged as srcset.
The sizes attribute is used to complement the srcset attribute on an <img> tag for responsive images, therefore it’s not valid if srcset is missing. Check the HTMLImageElement.srcset guide to learn about the correct usage of the srcset and sizes attributes.
Check the HTMLImageElement.srcset guide to learn about the correct usage of the srcset and sizes attributes.
When was the last time you validated your whole site?
Keep your sites healthy checking for A11Y/HTML issues on an automated schedule.