NVDA – a free and open source screen reader for Windows

Posted on Wednesday, 16 January 2008 by Steve Faulkner

People often ask on the various accessibility related forums and mailing lists, a question like:

If I wanted a Screen reader program which one should I buy?

For many developers is it worth buying a screen reader product like JAWS or Window Eyes? Its usefulness for providing meaningful results, in regards to the accessibility of a web site or web based application to a screen reader user, is limited by the relative inability of the non-disabled user to appreciate and understand the user experience of a person who has to use a screen reader to interact with the web and desktop applications. The only practical way to gain any sense of this is by sitting down with actual users of assistive technology and observing how they interact with the web and desktop. Another barrier for the disabled and non-disabled users alike is the complexity of screen reading applications, try looking through the JAWS keystroke documentation to get an idea; there are 150+ keystroke combinations just for using the web!

Having said this, it is useful and desirable for developers to have some first hand experience with a screen reader or other assistive technology. For example, it can be useful to test the new web standards based AJAX widget you just developed, to find out if the information that is available visually is technically available to the non visual user, though this information is probably better obtained using tools such as aDesigner or Accprobe, which provide a view of the MSAA or IAccessible2 hierarchy of currently running applications or rendered documents. Furthermore, acessibility user testing will always be required to ensure the actual accessibility of your widget for a screen reader user.

If you do want to experiment with a screen reader, rather than paying out large amounts of cash, why not try one of the free screen readers that are available such as NVDA (Non Visual Desktop Access), a free and open source screen reader for Windows.

Like JAWS and Window Eyes, NVDA uses a virtual buffer to provide access to web pages. When used in conjunction with Internet Explorer it exhibits similar problems (as JAWS prior to version 7.1 and all Window Eyes versions in both IE and Firefox) with JavaScript (including AJAX) based content changes. Used with Firefox it updates the virtual buffer in response to content changes (as does JAWS 7.1+ in both IE and Firefox). So it is useful to replicate the sort of content update issues that occur in JAWS and Window Eyes, when browser content is updated without a page reload.

General Features of NVDA:

  • Browsing the web (with Internet Explorer or Mozilla Firefox)
  • Reading and writing documents with programs such as Wordpad or Microsoft Word
  • Sending and receiving email with Outlook Express
  • Using command-line programs in Dos windows
  • Producing basic spreadsheets in Microsoft Excel
  • General computer management through My Computer / Windows Explorer, Control Panel applets, and other generic Windows tasks.
  • Further Reading:


    About Steve Faulkner

    Steven is the Senior Web Accessibility Consultant and Technical Director, TPG Europe. He joined The Paciello Group in 2006 and was previously a Senior Web Accessibility Consultant at Vision Australia. He is the creator and lead developer of the Web Accessibility Toolbar accessibility testing tool. Steve is a member of several groups, including the W3C HTML Working Group and the W3C Protocols and Formats Working Group. He is an editor of several specifications at the W3C including HTML 5.1, Using WAI-ARIA in HTML and HTML5: Techniques for providing useful text alternatives. He also develops and maintains HTML5accessibility

    Comments

    1. This is a good program to get a feel for screen reader usage.
      Be sure to read all of the user guide and please try to forget that there is a mouse attached to your computer when testing (unless you really need it).
      If you are using the eSpeak synthesizer, you will want to adjust the pitch and tone to something more pleasing than the default. If you are using SAPI4 or SAPI5 you may want to use something other than the default “Microsoft Sam” voice. Get the free “Mike and Mary” voices from MS for a slightly more pleasant experience.
      The portable version works fairly well too. I’ve got it installed on my 2.5″ 20 gig USB external HD for demo purposes.
      Great to see the support from the Mozilla Foundation.

    2. Hello Steve,

      I just went to download the program in the second link “NVDA Download”, and was brought to page not found error 404. I was very much looking forward to trying out this program, so hope you can look into this error.

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