Why HTML Validation Does Play a Role for Your Website

Websites are always competing tooth and nail to achieve higher visibility on search engines using all the SEO, PPC and other methods they can. Whilst there are many search engines to use online, you could literally discard them all and regard Google as the number one search engine leading the way given its current market share in the United Kingdom which stands at 87% according to Statista.com. The consequence of this is stark, when Google makes changes to its algorithms or guidelines pertaining to what webmasters should do in order to rank organically, business owners, webmasters and SEO’s need to take note and act accordingly.

New Updated Webmaster Guidelines


In late January Google updated its Webmaster Guidelines from the following;

“Check for broken links and correct HTML”


“Ensure that all links go to live web pages. Use valid HTML.”

Google specifically talks about “validation” of HTML. Now, this might not have been a big concern for webmasters if that phrase had been there since the beginning. However, the change in the use of language here is significant. However, according to John Mueller, Google employee, in this video hangout, a related question “Is WC3 validation a ranking factor?” was answered at the 1 hour mark – using valid HTML is not directly a ranking factor but it can affect Google’s ability to crawl and validate structured data and mobile browser rendering.

Is John Mueller’s Statement Contradictory?

Playing devil’s advocate here, it’s not unreasonable to assume the answer is yes. Technically, non valid HTML may not be a direct ranking factor, however, if non-valid HTML is causing Google crawl issues because HTML is badly broken or interfering with its ability to view structured data or rendering incorrectly on various mobile devices then these are ranking factors albeit indirect ranking factors.

My personal view is the language used in the updated guidelines is also significant “Use valid HTML” which is pretty explicit for Google. Therefore, ignore this statement at your peril if you intend to try and rank in Google and choose to ignore validating your HTML. In trying to achieve high rankings in Google at this juncture it’s probably not worth spending huge sums trying to validate your HTML if you have an older website. Why? Put simply, there many other ranking factors which are more important at this present time, but if a cleanup is possible without spending lots of budget, then go ahead, especially if it means ensuring structured data and mobile browser rendering is fixed.

How Can I check for Valid HTML?

In order to get the best understanding of what constitutes valid HTML refer to W3C and use their free validator tool here: https://validator.w3.org/. To check mobile devices this testing tool will help – https://validator.w3.org/mobile-alpha/. For those interesting in CSS, there is even validators here on offer from W3 eg https://jigsaw.w3.org/css-validator/. Lastly, Google have provided their own tool for webmasters to test whether structured data is correct – https://search.google.com/structured-data/testing-tool

Most web developers these days will produce websites with valid HTML, however, there can be issues with older websites which may not be keeping up with the latest mobile browsers, therefore, it’s important for the reasons in this article that your website code is updated regularly.