A Technology Pattern from
Patterns for Personal Web Sites

Graceful Failure

While it's comforting to imagine that your site's visitors will be using a recent browser that implements the latest standards, the reality is different. Older browsers are still in use; some people disable active content (e.g., Javascript); disabled people may use special technology to read your site. Each will see your site in a different way. If you don't ensure that your content is still communicated on browsers without the capabilities you expect, your site becomes inaccessible.

Therefore, use technology that fails gracefully. If a visitor's browser isn't capable of rendering the site as you intended, it should still be usable.

There are a number of ways to make your site accessible. For example, use of the IMG tag's ALT and LONGDESC attributes allow your site to be usable if images aren't loaded. Cascading style sheets, used with care, provide a very flexible method for making your site look good while still preserving usability on browsers that don't render CSS.

Using Appropriate Technology sometimes obviates the need for Graceful Failure.



Last updated 18 June 2002
http://www.rdrop.com/~half/Creations/Writings/Web.patterns/graceful.failure.html
All contents ©2002 Mark L. Irons