Are W3C Validators too strict? Do errors create SEO problems?

[INCart]

I ran a HTML markup validation tool (http://validator.w3.org) on a website. There were 140+ errors and 40+ warnings. IT says "W3C Validators are overly strict and would deny many modern constructs that browsers and search engines understand."

What a browser can understand and display to visitors is one thing, but what search engines can read has everything to do with the code.

I ask this: If the search engine crawler is reading thru the code and comes upon an error like this:

…ext/javascript" src="javaScript/mainNavMenuTime-ios.js"> </script>');}
The element named above was found in a context where it is not allowed. This could mean that you have incorrectly nested elements -- such as a "style" element
in the "body" section instead of inside "head" -- or two elements that overlap (which is not allowed).
One common cause for this error is the use of XHTML syntax in HTML documents. Due to HTML's rules of implicitly closed elements, this error can create
cascading effects. For instance, using XHTML's "self-closing" tags for "meta" and "link" in the "head" section of a HTML document may cause the parser to infer
the end of the "head" section and the beginning of the "body" section (where "link" and "meta" are not allowed; hence the reported error).

and this...

<code class="input">…t("?");document.write('>');}</code>

The element named above was found in a context where it is not allowed. This could mean that you have incorrectly nested elements -- such as a "style" element in the "body" section instead of inside "head" -- or two elements that overlap (which is not allowed).

One common cause for this error is the use of XHTML syntax in HTML documents. Due to HTML's rules of implicitly closed elements, this error can create cascading effects. For instance, using XHTML's "self-closing" tags for "meta" and "link" in the "head" section of a HTML document may cause the parser to infer the end of the "head" section and the beginning of the "body" section (where "link" and "meta" are not allowed; hence the reported error).

Does this mean that the crawlers don't know where the code ends and the body text begins; what it should be focusing on and not?

[Doc_Sheldon]

Generally speaking, I would agree that validation is often too strict.

Google seems to handle this well, however. In fact, I seem to recall Matt C. once saying that the VAST majority of websites don't validate. I think he may have been talking strictly about HTML, though.

Validation isn't a ranking factor, of course, and most prevalent browsers will compensate for minor errors and render a page, regardless. So I really wouldn't be too concerned about validation just for validation's sake. As long as your pages render in most common browsers and neither page functionality nor user experience is adversely affected, I'd consider it a non-issue. As to whether a bot could be fooled into thinking the head had ended and the body had begun, I suppose it's possible, but I've never seen it happen, even with some absolutely horrible coding.

[danatanseo]

I agree with Sheldon, and, just for perspective....try running http://www.google.com through the same w3c HTML validator. That should be an excellent illustration. A page with almost nothing on it, coded by the brilliant folks at Google still shows 23 errors and 4 warnings. I'd say not to obsess over this too much unless something is interfering with the rendering of the page or your page load speed.

Hope that helps!

Dana

[LesleyPaone]

Google is a different case being run through the validator. I actually read an article on why google's site do not validate. The reason is that they send so much traffic, it actually saves them a good amount of money not closing tags that do not matter. Things like adding a self closing / to an img tag and the sorts.

While I do not think that validation is a ranking factor, I wouldn't totally dismiss it. It make code easier to maintain, and it has actually gotten me jobs before. Clients have actually ran my site through a validator before and hired me.

Plus funny little things work out too, someone tested my site on nibbler and it came back as one of the top 25 sites. I get a few hundred hits a day from it. I will take traffic any where I can get it.