Getting Started with NVDA: A Guide for Accessibility Testing
NVDA (NonVisual Desktop Access) is a free, open-source screen reader for Windows. It allows people who are blind or have low vision to use computers by converting on-screen text into speech. For developers and content creators, testing with NVDA is a great way to ensure your digital content is truly accessible.
What is a Screen Reader?
A screen reader renders digital content as speech or braille. Instead of a mouse, users navigate via keyboard commands to “jump” through landmarks like headings, links, and forms. Testing with a screen reader helps you find issues that automated tools often miss, such as incorrect reading orders or vague link text.
How to Install NVDA
- Download: Visit the NV Access Download page.
- Donate (Optional): NVDA is free, but you can choose to support the project before downloading.
- Run the Installer: Open the .exe file.
- Choose Your Setup: You can install it to your hard drive or create a “portable version” on a USB drive if you do not have administrative rights on your computer.
How to Set It Up
The “NVDA Key”
Most commands require you to hold down a modifier key. By default, this is the Insert key, but in the “Welcome” dialog, you can also enable Caps Lock to act as the NVDA key.
The System Tray Menu
The NVDA icon lives in your System Tray (the notification area by your clock). Right-clicking this icon is the easiest way to access:
- Preferences > Settings: To change voice, speed, or vision tools.
- Tools > Speech Viewer: To see a text log of what is being spoken.
Preferences > Settings
- Adjust Speech Voice and Rate Settings: Select Speech to adjust the speech settings. Select your “voice” and adjust the rate, pitch, and volume to your liking. To start, lower the Rate to 30% or 40% while you are learning. Screen reader users often listen at high speeds, but beginners often need it slower. You can revisit the speech settings to adjust as needed.
- Adjust Vision Settings: It can be helpful to “Enable Highlighting” in the vision settings. This will add a highlight focus to where the screen reader is reading and help you track what you’re hearing.
- Adjust Mouse Settings: By default, NVDA will read whatever is under your mouse cursor. If you are confused by a specific icon or button, hover over it. NVDA will tell you exactly what it “sees” (e.g., “Search button” vs. “Unlabeled button 42”). If the constant talking as you move the mouse is too much, you can toggle this in Preferences > Settings > Mouse.
Tools > Speech Viewer
If you want to see a text description of what the screen reader is saying, you can enable the Speech Viewer by visiting Tools then Speech Viewer.
Essential Keyboard Shortcuts
Keyboard shortcuts are essential for using and navigating with a screen reader. Practice using these essential keyboard shortcuts.
Turn On / Turn Off
- Turn on NVDA: Ctrl + Alt + n
- Turn off NVDA: Insert + q
- The “Hush” Key: Press Control or Shift to instantly silence NVDA.
The “Say All” (Flow Test)
- Keyboard Shortcut: NVDA (Insert or Caps Lock) + Down Arrow
- The Test: This reads the page from your current spot to the end. Use this to check the reading order. Does NVDA read the sidebar in the middle of a sentence? Does it skip over the main navigation?
Single-Letter Navigation (The Auditor’s Toolkit)
Press these keys to jump to the next element. Hold Shift to go to the previous one.
Elements List
- Keyboard Shortcut: NVDA (Insert or Caps Lock) + F7
- Purpose: This displays a list of every Link, Heading, and Button on the page. It is the best way to see if your page is navigable “at a glance.”
Quick Checklist for Testing Accessibility
- Unplug your mouse: Can you reach everything with Tab?
- Check Headings: Does H take you to the main sections in order?
- Verify Links: Open the NVDA + F7 list, or navigate to links using K or tab. Do the links make sense out of context?
- Audit Graphics: Use G to ensure no “unlabeled graphics” or filenames are read aloud.
- Listen to Form Fields: Use F or Tab to enter forms. Does NVDA read the label and the instruction (e.g., “Password, edit, required”)? If it just says “Edit,” the form is inaccessible.
- Test Navigation Menus: When you click a dropdown menu, does the focus move into the menu? Can you use the Arrow Keys to move through menu items? Does pressing Escape close the menu and return you to the button that opened it?
- Check the Elements List: Press NVDA + F7. Review the “Links” and “Buttons” lists to ensure every item has a unique, descriptive name.
Testing Tip
If you ever get “trapped” or NVDA won’t stop reading a specific area, press Escape or use NVDA + Q to restart the tool.