It is a very common misconception that if you have a HTML version of a Flash site, accessibility is covered. I have seen companies (proudly) sell this to clients as the answer to complying with accessibility requirements. While this is great for Universal Access and will certainly allow more users to view the content, this will not make a Flash site more accessible to disabled users.

This technique is referred to as Progressive Enhancement although you may have heard it as graceful degradation. Bobby van der Sluis explains Progressive Enhancement in a great article on Adobe Devnet.

Progressive Enhancement is a web development strategy that ensures that even a visitor with the lowest common denominator web browser technology can navigate through a website and read its content.

I am a strong supporter of Progressive Enhancement and will utilise for every project possible. It is however important to understand that it deals purely with issues relating to required and supported technology. It does not actually deal with users and abilities.

If a user has both JavaScript and the latest version of FLash on their computer they will experience the Flash version regardless of ability or Assistive Technology. The result of this is that there are many users who are experiencing broken sites and content.

The Flash movie is displayed exactly as it does for every other user who has both Flash and Javascript turned on. The problem is that the screen reader user, keyboard user or any other disabled user will be faced with an inaccessible Flash site. No matter how good your HTML site is – the user will NEVER get to see it.

It is essential to understand that if you are developing Flash content you will need to think of disabled users and how they will interact with your site.