The three Firefox add-ons discussed in this document are all free. They are suitable for slightly different purposes. Fangs is an excellent light weight tool to “read” HTML documents, but it does not perform any rule checking. Fangs is great for checking the effects of various accessibility constructs and practices. For example, one can add the “alt” attribute to an image, and see how the document is rendered differently in Fangs.
FAE, on the other hand, encompasses a large selection of features. The most useful feature is the rule check tool. This tool permits a web developer or designer to quickly identify violations and warnings regarding web accessibility. It is also helpful to see a list of links and headers because many users who need accessibility use those lists for quick navigation.
Last, but not least, Firevox is a real screen reader. It is not an effective tool for most web developers or designers, but it is a good reminder of how visually impaired users perceive HTML documents. As a result, it is a tool that a web developer or designer may want to use once in a while, or at the end when an HTML document is made accessible.