For those who have never heard of the the World Wide Web Consortium (W3C), they are an international community where member organizations, a full-time staff and the public work together to develop Web standards. The W3C is lead by Tim Berners-Lee (the guy who invented the World Wide Web) and CEO Jeffrey Jaffe. They develop protocols and guidelines for popular languages like HTML, XHTML and CSS.
W3C has a validation service that validates Web pages against standard formats. You can enter a website url and it will check the code in the page and see if it validates to the W3C standards. Check it out here http://validator.w3.org
According to the W3C, “Although validation is not mandatory on the Web, it is useful for improving the quality of pages.” So it begs the question, does it matter? Some SEO experts claim that validated code can get a website better search engine rankings while others strongly disagree. Here’s a video I found titled Why doesn’t google.com validate? Matt Cutts, a Google engineer, explains the issue from the Google’s perspective.
The truth is many of the most popular and high traffic websites do not validate. Take a look at the top 10 websites from Alexa.com:
None of these ten websites validate. Some are close with only 1-2 warnings but a couple have 400+ warnings. In fact, it wouldn’t be too farfetched to say that probably 90% of the pages on the Internet don’t validate. For example, any web page that has any kind of Facebook code in it, a Like button, a Share button, etc. will never validate. Facebook uses their own markup that doesn’t validate to the W3C standards.
For smaller websites however, validation could be a little more important, especially during development. A validated page will greatly help it render properly on different browsers for cross-browser compatibility. It also helps identify coding and scripting errors that may occur. Debugging a web page that has validated code will usually be easier, less time consuming and less tedious that having to debug a web page that doesn’t have validated code.
So does it really matter? It probably should but it doesn’t really seem to. I guess it all depends on who you ask.