How will HTML5 address accessibility?

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In 2010, a new type of HTML is taking over the web, but how will it work for users with accessibility needs?

Every web page is made up of programming code (including HTML, CSS and JavaScript) which contains and controls what appears on screen as well as the metadata for the page. This programming code sits around and in between the page's content to manipulate and display the content as required.

These languages, especially HTML, have been evolving since the beginning of the web, gradually adding and removing features as new versions of web browsers (such as Internet Explorer, Firefox and Chrome) have given web developers new possibilities.

2010 has been the breakthrough year of the latest version of HTML, known as HTML5. HTML5 aims to bring into the language a slew of features that were typically handled by separate technologies such as Flash, while also giving richer meaning to websites by more explicitly telling the web browser application which parts of content are what: navigation bars, side content areas, header areas and so on. Overall, HTML5's goal is to make web pages, and therefore web applications for desktops and mobile devices, richer.

A major part of HTML5 comes in the form of new multimedia features, specifically the audio, video and canvas tags, and the SVG image format. The audio and video tags enable multimedia content that was previously only available via Flash to be embedded directly into the page. This gives web developers a lot more flexibility in how the audio and video areas can interact with the rest of the page.

The canvas tag offers developers the ability to dynamically render and animate graphics in real time on the web page, without the need for pre-compiled Flash or pre-rendered graphics. This gives web designers a huge scope for the future.

SVG is a light-weight image format that enables high-resolution vector images (as used by applications such as Adobe Illustrator) to be displayed on a web page, offering new options for embedding images.

For years, accessibility experts have pushed for strong accessibility in HTML (and its sister standard, XHTML) and for most things, this is now in place in all major browsers, with some notable exceptions. With HTML5's focus on multimedia, this introduces a whole lot of new challenges, but they are being addressed.

The audio and video tags so far do not have accessibility support, but will be gaining the ability to embed text captions very soon. The very fact that these elements will be built into the HTML, instead of external Flash, also means that there is great scope to improve in the future, without reliance on specific vendors to implement accessibility features.

In the case of canvas, this is a little more complicated. For several months, Microsoft held out on including canvas in the forthcoming Internet Explorer 9, simply because there are no defined ways of making a live rendering accessible. With the latest platform release of Internet Explorer 9, Microsoft has followed the quasi-standard being used by others: extended image map. At this stage, it is a strong proposal which should result in a relatively good level of accessibility for the canvas tag.

Actually ensuring HTML5 is accessible rests on three stakeholders:

  1. Browser developers including features in such a way that web developers can make them accessible as easily as possible
  2. Web developers ensuring that they follow accessibility standards
  3. Assistive technology vendors recognising the new features.

In respect of HTML5, we're 90% of the way through point 1, and maybe 25% of the way through point 2. Sadly, point 3 is a while off for major players such as JAWS, while more agile developers such as NVDA will certainly enable new features quite quickly.

It is also important to note that not all browsers are HTML5-compatible. No version of Internet Explorer is yet, and only the latest versions of Firefox, Safari, Opera and Chrome offer any support for the features, or for accessibility. Non-Internet Explorer browsers currently account for around 40% of users worldwide, and many of those can be assumed to be HTML5-ready. It won't be until the latest version of Internet Explorer, expected early next year, is released, and overtakes older versions, that we will be able to ensure all users can benefit from the latest HTML5 features and their accessibility updates.

At Webdragon we're working with our clients to use HTML5 features when appropriate. As HTML5 opens up more opportunities for developers and clients alike, we look forward to using it a whole lot more.

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