HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
The “inputmode” attribute is not supported in all browsers. Please be sure to test, and consider using a polyfill.
inputmode attribute specifies what kind of input mechanism would be most helpful for users entering content into the form control. This attribute is not supported in all browsers, so it’s advised to use with caution and consider alternatives for older browsers.