There are a great many WordPress plugins for contact forms but it appears that none of them by themselves create accessible forms for people using screen readers. I had assumed that accessibility was a major consideration when creating any plugin for the web but apparently most developers do not even consider it. My search for an accessible form plugin produced two choices. Neither of these were accessible in their initial form.
The first form I looked at was Gravity Forms. Unfortunately there is no free version of Gravity Forms so I was unable to try it out. To make Gravity Forms accessible you need another plugin called WCAG 2.0 form fields for Gravity Forms. There is an example of an “accessible” Gravity Form at ilusio.com but when tested with Wave Accessibility Evaluation Tool there were a number of errors and alerts. This may not be the fault of the plugin. Many people prefer the Gravity Forms interface to that of Contact form 7. To the right there is a picture of the Gravity Forms interface.
I have used Contact Form 7 on many web sites and I love the very simple interface. Admittedly the interface is better suited to developers who have a good knowledge of HTML. To make this plugin accessible you need to install Contact Form 7: Accessible Defaults before installing the Contact Form 7 plugin. The Accessible Defaults plugin will not change any forms that were created before installing the plugin. Below is a screen shot of Contact Form 7 interface.
There are a number of other plugins for Contact Form 7 that will help make the form more diverse. You can find a list of these plugins at Elegant Themes Blog. I have used the Conditional Fields plugin to create an accessible form that only reveals relevant fields. A couple of my clients use screen readers and they assure me that the forms are easy to use.
It is a great pity that there are no WordPress form plugins that are accessible in their own right. Two form plugins that have plugins to make them accessible are Gravity Forms and Contact Form 7. Gravity Forms does not have a free version so I was unable to try it out. Contact Form 7 with the Accessibility plugin produces good, clean accessible forms.
For more on Accessibility read Creating aAccessible Web Sites