A screen reader is a program that reads the screen aloud using text-to-speech. NVDA is a free and lightweight screen reader for Windows that works best with Firefox. This document provides instructions on installing NVDA and using its basic keyboard commands to test a web page for accessibility by having the screen reader read and navigate the page without using a mouse. It explains the difference between browse mode for reading content and focus mode for interacting with form fields.

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Web Accessibility Testing 4 - NVDA
Screen Reader
What’s a screen reader?
A screenreader is a program that reads the screen aloud, with a voice synthesizer. Screen
readers are generally used by blind users, although they may also be used by users with
low vision or cognitive disabilities (like dyslexia).
About NVDA
NVDA is a free, lightweight screen reader for Windows. NVDA stands for NonVisual
Desktop Access. It works best with Firefox, although it also works pretty well with
Chrome and IE.

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Other screen readers
This document will not be covering:
● VoiceOver for iOS or macOS
● TalkBack for Android - for details, see docs on gestures and explore by touch
● JAWS for Windows - expensive, but still popular (can be run for free in 40-minute
demo mode)
Installing NVDA
1. On Windows, download NVDA from here: http://www.nvaccess.org/download/
(The donation is optional.)
2. Run the installer.
Recommended optional install steps
1. Add an NVDA shortcut to your desktop.
2. Right-click on the icon and select Properties. Find the “Shortcut key” field, click
in it, and press the Ctrl+Alt+n keys together. Then click OK. From now on you
can from NVDA by pressing Ctrl+Alt+n.
3. The default NVDA voice is not as pleasant (or as easy to understand) as other
available voices. Consider installing Eloquence (the voice from JAWS) or
switching to Anna (the voice that comes with Windows 7). The voice can be
switched in NVDA > Preferences > Synthesizer.
4. By default NVDA will read anything you hover your mouse over. This is probably
a feature for users with low vision, and it can be very distracting when you’re
testing. With NVDA running, press Insert+m to turn mouse tracking off. NVDA
will say “mouse tracking off”.
5. You might like an addon called Focus Highlight which displays a box around the
content being read. Keep in mind this will interfere with the site’s visual focus
indicators (dotted lines around links and buttons). But you might prefer to test
visual focus indicators without NVDA running, in which case it won’t be an issue.

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How to test with NVDA
1. Load your web page in Firefox (it's the best browser for NVDA).
2. Press Ctrl+Alt+n to run NVDA.
3. Click anywhere on your browser window so it becomes the active window.
4. Tab into the web page so NVDA can read the web page contents.
5. Set the mouse aside so it doesn't interfere with your test.
6. Press Control to stop NVDA from reading. (You will use this a lot.)
7. Press Control+Home to jump to the top of the page. Press the down arrow key
repeatedly, reading the page contents from top to bottom.
8. Press Ctrl+Home to jump to the top of the page again. This time, tab through the
page - you should reach each link and form control. Test each one (or at least a
good sampling of them) by pressing Enter when you reach it.
9. Without using the mouse, you should be able to have NVDA read anything on the
page, and you should be able to use all links and form controls.
10.Press Insert+F7 - this will display a convenient menu of Links, Headings, and
Landmarks.
11.When you’re done, press Insert+q to close NVDA.

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Browse Mode vs. Focus Mode
● Browse mode - for reading page content
● Focus mode - for interacting with a text box, drop-down, or textarea
NVDA starts reading a page in browse mode. When you are pressing the down arrow
key, you are in browse mode.
if you tab into a text field (or dropdown or textarea), NVDA will go into focus mode
(this is called forms mode in JAWS). Focus mode allows you to enter text in the text
field. When in focus mode, you won’t be able to press the down arrow to the leave the
text box (you can tab out if you like though).
To exit the text box, press Escape to switch back to browse mode. Then you can press the
down arrow key to continue reading page content.
See more on browse mode:
https://www.nvaccess.org/files/nvda/documentation/userGuide.html#BrowseMode

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Common keyboard commands
● Ctrl - stop talking
● Ctrl+Home - place focus at top of page
● Down arrow - read next line
● Insert+F7 - show menu of Links, Headings, and Landmarks
● Tab - takes you to links and form controls (not text)
● Insert+Space - exit focus mode
● Insert+Q - closes NVDA
● Ctrl+Alt+up/down/left/right arrow keys - navigate data table
● Insert+N > T > S - open Speech Viewer
● d - go to next landmark
More NVDA commands: http://webaim.org/resources/shortcuts/nvda
Note: Colour Contrast Analyser will hang if you try to use it with NVDA. If this happens,
just close Colour Contrast Analyser.