Validating your website
However, there are compelling reasons why you should make every effort to learn HTML- and CSS-valid standards, and comply with them.
It's There's a W3C validator for mobile devices as well.
HTML, CSS, SEO, spelling, accessibility, mobility (Android/i OS), Java Script linting, and link checking with CSE HTML Validator for Windows.
Not even using only images will make a website look exactly the same everywhere.CSE HTML Validator to check HTML, XHTML, CSS, SEO, and more.CSE HTML Validator is for web professionals, webmasters, corporations, government agencies, individuals, teachers, students, non-profit organizations, or anyone with a website.Although web browsers will accept bad (invalid is the official term) web pages and do their best to render the code by making a best guess of the author’s intention, it is still possible to check whether the HTML has been written correctly, and indeed it is a good idea to do so, as you’ll see below. The validation program compares the HTML code in the web page with the rules of the accompanying doctype and tells you if and where those rules have been broken.There is a common feeling amongst some web developers that if a web page looks fine in browsers, it doesn’t matter if it doesn’t validate.
It's guaranteed to improve your website or your money back.