As I code pages for Web sites, I’m always working on ways to improve accessibility. The online tools for evaluating a site really just don’t cut it alone. It’s fairly easy to code a site that passes tests like the one found at The HiSoftware Company CynthiaSays portal (a very popular and accurate accessibility test) but that is still utterly unusable by someone using a screenreader, unable to use a mouse, suffering color blindness or any other disability that means they are using your site in any number of different ways. That’s not to say that online tests are not incredibly valuable, just that running your pages through a single test and thinking the job is done may not cut it.
Accessify.com has provided some incredibly useful tools and wizards to help build and test accessible Web sites. There are wizards for creating accessible HTML code (forms and tables), browser plugins for testing pages, even a set of Dreamweaver objects that increases the accessibility of your code by adding additional options to dialogs for creating tables, images, acronyms, etc.
For testing usability for people with different vision needs, I love GrayBit which renders your page in grayscale so that you can visually evaluate the color contrast of your site. Another really cool color tool is Color Schemes which not only helps you develop a color palette, but also lets you preview your palette approximating eight different types of color blindness.
When you get right down to it, though, there really is no substitute for having differently abled users test your site. They’ll let you know better than any test out there what needs to be improved. Just testing with average users who are unfamiliar with the site will go a long way toward exposing usability shortcomings, which often translate to accessibility issues.
Remember: an accessible site is also a more search engine friendly site! As if you needed a selfish reason to strive for accessibility.