SEO Myths #5
If your website validates, Google boosts it up
We can't find any evidence that having pages or a whole site that validates to W3C guidelines has any benefit at all in Google.
All of the search engines have invested a lot of time in to making spiders and indexers that can read all sorts of foul, heinous HTML which is full of broken tags, unfinished scripting, unofficial tags and open ended coding, and extract what they think is the textual content from the pages. They do this because not everyone knows how to write HTML and some of the editors that people used to make pages over the years have been rubbish at making decent HTML.
However, those same pages may have content written by a genius who is an expert at giving the advice you want to find. They want to give you the best matches to your search, no matter how badly the underlying code is written.
All that said, if you use semantically correct code, your site can gain a boost compared to a competitor who does not. If you put an important key phrase in your page within a heading tag (e.g. h1, h2, h3 ) then it will be seen as more important than other words on the page and in turn the page will be seen as more important for that phrase.
If your competitor is not using headings, they won't receive that boost, so you will naturally do better than them, all other things being equal.
People who make sites with valid HTML also tend to care about using headings and other tags correctly, so their sites look like they're getting a boost by being valid, but it's actually because they're marking up their content correctly and helping the search engines understand it.