Why Validate a Site on W3C? W3C validation is the process of checking a websites code to determine if it follows the formatting standards. If you fail to validate the pages of your website based on W3C standards, your website will most likely suffer from errors or poor traffic owing to poor formatting and readability.
1. Help Improve Rankings in Search Engines.W3C validation helps you to get better rankings in search engines. Errors in your code can affect your sites performance and also make a big impact on you sites SEO, search engines check the HTML or XHTML code of your website when searching. If they find invalid HTML or XHTML code – meaning code that does not follow the official rules, you might be removed from their indexes. If there is an error on your web page code, robots will stop searching your whole websites content.
2. Validation helps teach best practicesHaving standards-compliant code is the best practice for web design. It also teaches and encourages best practices for web design. While many veterans have learned to create error-free code and make relatively few validation errors, most beginners make more errors. Computer validation checks can help beginners learn from their mistakes. “These technologies, which we call “web standards,” are carefully designed to deliver the greatest benefits to the greatest number of web users while ensuring the long-term viability of any document published on the web. — Web Standards Group “
3. Improved Website User ExperienceW3C validated websites will be easily accessed by people with modern browsers. Validation improves usability and functionality because your users are less likely to run into errors when displayed on browsers compared to non-validated websites. Validation is fully compatible with a wide range of dynamic pages, scripting, active content, and multimedia presentations. The website validation process allows website designers to correct formatting errors that impact website performance and following international standards, the code used in websites is reduced in size while improving efficiency. Because of this, web pages are displayed much faster and flow much better compared to websites that have not been validated
4. Make Website Browsers FriendlyMaking website browsers friendly is one of the biggest reasons why W3C code validation was introduced. Websites that are not validated may display correctly in one browser but not in other browsers. Cross-browser problems are faced by many websites. Websites that are not validated may display formatting problems when used in certain browsers. On the other hand, W3C validated websites are displayed without errors regardless of what browser is used. There are five major web browsers: Chrome, Firefox, Internet Explorer, and Safari; and usage among each of them translates to millions of internet users.
5. Multiple Device AccessibilityWith the recent boom in smartphones and tablets more people will be accessing the Internet from mobile devices than desktop computers. By 2015, mobile commerce will reach $119 billion worldwide and some sectors are seeing an even higher proportion of mobile traffic so there is a growing need for website owners to maximize the usability of their websites in new devices. Unfortunately, many website owners do not take advantage of this growth and forego W3C validation that makes sure their websites and web pages are mobile friendly too. If you want your website to be visited by as many users as possible then accessibility should be a big factor.
6. Validation help for easy Coding and MaintenanceWebsites or web pages that validate using W3C website validation have code formatted efficiently and are easy to edit and it helps website owners to create a new page or another new website with similar formatting. The validated code used in W3C HTML validation, W3C XHTML validation, or W3C CSS validation can be used in future sites.
7. Validation as a debugging toolValidators tell you where you have errors in your code. If your page isn’t displaying as expected a validator might very well point you to the cause of the display problems. Also invalid code that may display fine in one document may cause show stopping errors in another because of the encompassing code.
My Validation on Index Page
On my index page code I had a few errors that where very easibly fixable. Things such as a useless line break tags and a empty style tag I didn't need.
Source: Login Radius