Ever since the HTML5 standard has been released in its “beta” stage, its adoption rate has sky rocketed. It’s no wonder, given that the blend between HTML, CSS and AJAX has become tighter and more reliable. Now, this blend has been mixed with native support for audio/video and has been pushed through towards the web.

However, mixed systems (like WordPress), suffer from some severe issues with respect to HTML5. It’s not enough for a theme to boast itself as using HTML5, since a lot of the output is done by the core of WordPress from within its main include files, those too need to be migrated to HTML5. Unfortunately for us WordPress users, this hasn’t happened yet in version 3.2.1. But if you use a HTML5-compliant theme, you’re good to go, right? WRONG!

So what are the obstacles preventing you from validating your site?

Source Issue Solution
 the WordPress core  Unfortunately the WordPress core still outputs a lot of non-HTML5 code. Since that precludes  your theme in many places, it means that even with a HTML5 compliant theme, your site will never validate as HTML5!
  •  manually peruse the WordPress core code and correct each and every issue reported by the W3C validator
  • bug the creators of the theme to try and override each and every functin of the WordPress corewhose output is not HTML5 compliant
  • don’t use “none” as target for your links in the blogroll, as “none” will result in an empty target which is invalid under HTML5 (needs to be “_none” but WordPress generates “”)
 desktop publishers  The vast majority of desktop plublishers (such as Windows Live Writer, for example) still refuse to output CSS for paragraph formatting. Since all non-CSS formatting has been deprecated in HTML5, it means that when you post via these, your site will not validate as HTML5!
  •  with the Kitchen Sink activated in the WordPress Admin section of your site, you can do proper formatting (including justification). Now the WYSIWYG editor is a very competent editing tool, therefore you shouldn’t need to use other tools. If you must, try to review your posts using the Kitchen Sink in WordPress admin section.
 Wordpress plugins  Many plugins (such as NextGEN gallery) still output a lot of non-HTML5 code, preventing HTML5 validation
  •  in some cases, simply not using some options (in NextGEN all is OK if you choose Shutter effect instead of Lightbox, Lightbox is the offender) can result in good code
  • look for plugins with similar functionality but which output good code
 your articles  if you’re one of those people that need to do a lot of hand formatting, you need to brush up your knowledge of HTML, chances are you’re using old standards
  •  follow the indications of the W3C validator and correct those errors that come from manual HTML editing of your posts
  • avoid copy/pasting HTML directly into your posts