How to Check for Website HTML Errors That Impact SEO

The official rules for writing HTML are defined by the World Wide Web Consortium (W3C). If you don’t follow these rules for your website, will you be penalized by the search engines?

Although it doesn’t have a direct impact on Google rankings, W3C validation is incredibly important for browser compatibility and overall site usability.

Previously you mentioned that w3c validation isn't a ranking factor. Some people took this to mean that coding errors can't affect SEO. Many don't believe that. Can you give some examples of HTML errors that CAN affect SEO? Google’s Matt Cutts explains more in the video below.

Google crawls all sites, irrespective of coding. But there are some occurrences where sites aren’t indexed because of syntax errors.

If you’re website passes W3C validation then it will be very clean coded and most importantly easy will be easy to update in the future.

To help webmasters ensure their websites coding is correct, W3C has provided a number of free online validation tools. Here is a list of these tools and some others from 3rd party providers:

• W3C Markup Validation Service
• W3C CSS Validation Service
• W3C Link Checker
• W3 Schools Web Page Validation
• Multipage Validator

While the tools provided by W3C are likely to be the most accurate, I would also suggest testing your site with the online tools provided by 3rd parties, just to be thorough. If there is any discrepancy between the results, then it might pay to take a closer look at your HTML code.

If all of this content is flying over your head, then I would suggest sourcing a website developer/coder to take a look at your site.

In an effort to judge site authority and quality, its likely that Google will include W3C validity in their algorithm in the future; so now would be the time to get your code up to scratch.