It's a lot easier to design an accessible website if you consider accessibility from the get-go, but we don't always have that luxury. You’re far more likely to have an existing site on your hands, and, if you're reading this, you're probably wondering how to determine how accessible it is currently so you can get a better idea of what needs to be done.
Here’s a simple guide to testing your Drupal site for accessibility. (Most of these apply to non-Drupal sites, too). We've divided it into 3 sections.