I was recently asked to qualify why I had “upgraded” a website to utilise HTML5. All I had actually done was throw in a few semantic tags where it seemed appropriate and remove some unnecessary attributes. The client was concerned that the spec wasn’t complete and even suggested using HTML5 tags with an XHTML strict doctype. This was my response:
The HTML5 specification is different to your typical software specification. The W3C is no innovator: it does not lay down rules for browser vendors to follow. Vendors lead the way and their technology ideas are ultimately accepted, rejected, or tweaked to become part of the W3C specification. It’s highly unlikely the HTML5 specification will ever be fully complete. The only point when it could happen is when vendors and the W3C draw a line in the sand and move onto HTML6 (or whatever they name the next standard). If you wait for the final HTML5 specification, you’ll miss out.
http://blogs.sitepoint.com/2010/07/20/5-reasons-why-you-can-use-html5-today/
To say it’ll never be complete is a little pessimistic. Some experts in the industry believe it could be complete as soon as 2012. You get the idea though.
In terms of what the site is doing with HTML5 we’re not actually leveraging much of what HTML5 has to offer. Firstly we’re saving bandwidth by omitting attributes that all browsers already assume default values for, like the script type=”text/javascript” and stylesheet type=”text/css” attributes. Not to mention the new doctype, which is completely backwards compatible with existing doctypes in that it invokes standards mode in all browsers. Actually, in terms of your website it would be better to use a HTML5 doctype than an XHTML strict doctype, since the page is being served as text/html content-type by Apache, which is incorrect – the correct content-type for XHTML documents being application/xhtml+xml.
The second, and only other feature of HTML5 we’re actually using is semantic tags (http://bit.ly/1CzNqy). These allow us to create a document that is more accessible, in terms of search engine optimisation and for use of assistive technologies like screen readers. By using semantic tags instead of generic containers such as the div tag, our document is easier to understand when viewed by tools that don’t “see” page styles i.e. the design and layout of the page. For example, if your business name is within a paragraph tag it is likely to get lost in other content and not be returned in search engine results. But if you put it within a heading 1 tag, search robots know to give it more importance. Obviously this example doesn’t involve any HTML5 tags, but you should easily be able to see how the same principle can be applied to the new HTML5 elements, and how this principle will gain more and more importance as HTML5 becomes more widely adopted.
…and that is really the idea behind HTML5, everything that is being proposed, is being done so in a) a backwards compatible way and b) to cement features that already exist in one form or another. Pragmatically, that is what makes it viable to use features of HTML5 right now. Most existing browsers treat unknown tags as a generic HTML inline element and they can be styled to suit purpose.
Your one and only concern should be that there is a bug in IE 6, 7 and 8 that means they don’t recognise HTML5 tags. Fortunately there is a workaround, although it requires JavaScript to be enabled. If your visitor is using IE, without JavaScript enabled, your site will look differently to how it would normally look. It won’t make the site inaccessible, but some stylistic properties won’t be applied to page elements, so the page will appear a bit more like a text document than a website. Globally, I’ve seen stats showing that between 0.4% and 7% of browsers have JavaScript turned OFF. Potentially a very small percentage of your web traffic – which will probably be even less considering it only effects IE users, but it depends on your audience. Check your webstats and make a judgement call. For the majority of the time, the benefits outweigh the cost of supporting the fringe cases and I would recommend using HTML5 on your website now, as I have done for a number of clients I have worked with recently.