To ensure that your forms are accessible to a wide variety of users, you should test them with a variety of assistive technologies. You can test your forms simply and inexpensively using the techniques described in this section.
Ensure that the form can be filled using only the keyboard. Be sure to fill the entire form and test all fields and buttons. As you complete the form, determine whether improvements are required based on your answers to the following questions:
Demo versions of screen reader software can be downloaded free from the Internet. To test screen reader results, turn your monitor off and use only the screen reader to navigate and fill the form. Because you are the form author, your familiarity with the form may make it difficult to determine if the information read by the screen reader is sufficient and makes sense. If possible, have someone else test your form in this way.
Many users with vision impairment rely on high contrast between text and the background to read the form. Microsoft Windows has a high contrast color scheme that provides a display similar to what many users with vision impairment will be using to complete your form. To set your display to high contrast mode, enable the feature through Accessibility Options in the Windows Control Panel. As you complete the form in this mode, determine whether improvements are required based on your answers to the following questions:

Techniques for testing form accessibility