Yesterday I wrote about the improved markup on my sites. Although I didn’t mention it explicitly, it almost goes without saying that almost all my webpages are now conforming to the W3C HTML and CSS3 specifications. Although I think in terms of HTML5 and use the HTML5 semantics in most cases, the doctype is still XHTML 1.0 Strict. Now, on one single page, I do actually use the HTML5 <video> tag. Of course, this makes that page a non-conforming XHTML 1.0 Strict document, but in practice there is no problem at all: every HTML5-aware browser I know of will display the video just fine, as if the doctype was the HTML5 one. I will soon upgrade to the HTML5 doctype, and then 100 % of my webpages will be standards-compliant.

It is somewhat interesting to examine the standard compliance of external major websites. It turns out that many, if not most, actually are non-conforming. Here are a few examples:

In most cases, I have examined only the main page of the site. I suppose most big sites use frameworks making each page comparable to each other page in terms of overall markup and page layout.