Assistive Technology (AT) is a broad term for hardware and software that supports people with disabilities. One of the best ways to ensure your website works for everyone, regardless of ability, is to try using it with one or more types of AT. People without disabilities are often introduced to the world of AT through screen readers. Using a screen reader will help you understand how your website’s information is conveyed to blind or low vision users. NVDA (Non Visual Display Access) is an open source screen reader that is free to download and use.
Assistive Technology Checklists and Reference Sheets provides guides for testing with screen readers in general and using NVDA specifically.
A screen reader is software that allows a blind or visually impaired person to use a computer. It includes commands that allow the user to move the cursor, read text, determine formatting information and to perform other essential computing tasks, while also supporting the operating system’s built-in keyboard short-cuts. Commands can be issued from a keyboard or Braille display, eliminating the need for a mouse. The information is conveyed using either synthetic speech or Braille output.
Apple computers include as part of their operating system Voiceover.
There are a number of third party screen readers available for Windows including