Accessibility testing with NVDA (Free Sample)

Produced in partnership with Intopia.digital

On This Page (Table of Contents)

  1. Getting Started
  2. Setting Up NVDA
  3. Reading Information
  4. Visual Options
  5. Keyboard Navigation
  6. Navigating Content with NVDA
  7. Working with Elements
  8. Testing with a Screen Reader
  9. Resources

Getting Started

About this page

This page is the free version of our paid "Accessibility Testing with NVDA" resource. The full package includes:

  • All the information and links from this free version.
  • Additional information and tips
  • Key takeaways for each topic summarised
  • Additional context for each topic
  • Step-by-step guide to using each topic
  • Recap summary and activity
  • Printable reference sheet for NVDA
  • Printable guide to making accessible content
  • Extensive Table of WCAG success criteria with suggestions on how to test with NVDA
  • Exclusive NV Access Web A11y Ally badge you can use to show off your Web Accessibility support
  • You are supporting NV Access to continue to make NVDA itself free of charge to anyone who can use it.

This material was produced in partnership with Intopia.digital. NV Access would like to thank Intoppia for their continued support. Intopia offer a range of web accessibility training through their Learn.Intopia.Digital platform.

The word 'intopia' in black text on white; the 'o' is made of semicircles of turquoise, then yellow, inside pink and orange.

Web Accessibility Testing

NV Access are not web accessibility specialists. We ensure NVDA is designed with accessibility standards in mind, such as WAI-ARIA. This page covers some features which can be used when testing for accessibility issues. It is not designed to teach you web accessibility from scratch or cover every aspect of guidelines such as WCAG

For expert training in web accessibility standards, testing, legal compliance, or for an audit of your own site, please contact companies such as Intopia.digital, WebAIM or Deque. Some of our NVDA Certified Experts in your local area may also be able to assist you.

NV Access would particularly like to thank Intopia.digital for their continued support, and technical feedback on this material. Intopia offer a range of web accessibility training through their Learn.Intopia.Digital platform.

Why test for accessibility?

Improving accessibility makes it easier for ALL users to access your content. In addition to the benefits, more and more places are making accessibility legally mandatory. Making your content accessible helps you meet your legal obligations.

What is NVDA?

NVDA is a screen reader. That is, software which reads aloud everything on the computer, particularly aimed at blind or low vision users. Information can also be presented on a refreshable braille display. We have a demo video of NVDA here. NVDA was not developed as a primary accessibility testing tool, although it is popular as one part of a wider testing toolkit.

Why use NVDA?

NVDA is an open-source screen reader, completely free for anyone to use, including for accessibility testing. We rely on sales of the paid "Accessibility Testing with NVDA" package, and our user telephone support and training material to help continue this into the future.

If a web page or app works with NVDA, it will generally work with other screen readers.

A reminder that this is a free sample of the paid "Accessibility Testing with NVDA" resource. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Setting Up NVDA

Obtaining NVDA

Because NVDA is free, you can simply download a full, unrestricted copy from our website at https://www.nvaccess.org/download/.

To help get you started, we recommend reading through the "Quick Start Guide". This is the first part of the User Guide which is available from NVDA’s help menu, or from the Quick Start in the NVDA User Guide online.

Installing NVDA

NVDA installs just like any other program in Windows. The latest version is always available from our download page. We have a walkthrough of downloading and installing NVDA in our Quick Start Guide if you need.

If your IT department needs additional details about NVDA before installing, our Corporate & Government page has lots of information. Feel free to reach out to us if you have any other questions about deployment not covered there.

Starting NVDA

You can start NVDA from the desktop icon it creates, the start menu, or by pressing control+alt+n.

The first time NVDA runs, it displays a "Welcome dialog" of options you can set. These allow you to control:

Another dialog appears the first time you start NVDA asking if you agree to for NV Access to gather additional usage statistics. This is minimal and you can find out about it on our Corporate and Government page.

The NVDA Modifier Key

Many NVDA commands use the "NVDA Key". This key can be set when installing or from NVDA’s keyboard settings. The NVDA key is either insert key or the caps lock key.

To quit NVDA, press NVDA+q (that is, insert+q, or caps lock+q), which opens a dialog asking what you would like to do. This gives options such as restarting with add-ons disabled or debug logging. To simply quit NVDA, press enter without changing anything on this dialog.

Keyboard Layout

It is possible to have NVDA set in "Desktop Keyboard Layout" or "Laptop Keyboard Layout". This can be set during installation or from the "Keyboard" page in NVDA’s settings. Desktop layout is the default. Where commands differ between keyboard layouts, these are indicated below.

The NVDA Menu

NVDA generally does not have its own window open. Press NVDA+n to open NVDA’s menu (that is insert+n or caps lock+n. This menu gives access to NVDA’s settings and features.

This free sample of the paid "Accessibility Testing with NVDA" package contains only a fraction of the full material. Purchasing the full package will give you more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Reading Information

Stopping and Pausing speech

NVDA has many keystrokes to control what is read or to manually read information. Some of the most commonly used when testing include:

While shift has the benefit of being able to restart speech by pressing it again, traditionally many end users are used to control (which is in the very corner of the keyboard).

  • To put NVDA to sleep while in the current application: NVDA+shift+s (Laptop Keyboard layout: NVDA+shift+z). Press again to wake up.
  • To quit NVDA entirely: Press NVDA+q, then press enter

Sleep mode may be useful if wanting to work "without NVDA" while in the current program. If needing to work entirely without NVDA between programs, quit NVDA, then restart it again when needed.

Reading information

Here are some commands you can use to read specific text in your document:
– To read only the current line: Press NVDA+up arrow (Laptop: NVDA+L)
– To start reading from the current point: Press NVDA+down arrow (Laptop: NVDA+a)

Customising speech

Press NVDA+control+v to open the speech options. Particularly investigate adjusting the speech rate at first.

NVDA has a "Synth Settings Ring", a series of commands to quickly adjust speech settings:
– To increase the current speech attribute (speech rate by default): NVDA+control+up arrow
– To decrease the current speech attribute: NVDA+control+down arrow
– To select a different speech attribute to adjust: NVDA+control+left or right arrows
– If using Laptop keyboard layout, add shift to the synth settings ring commands (Press NVDA+shift+control+up arrow to increase the current value)

In general, the synthesizer and speech options do not broadly change what is read or the accessibility of content.

We hope you are finding the information on this page helpful. If so, please consider purchasing the full "Accessibility Testing with NVDA" package for even more insights and tips. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Visual Options

NVDA has several options which can help visual users follow what is being read:

  • The NVDA magnifier enlarges everything on the screen. It can follow the mouse and keyboard focus as well as NVDA’s review cursor and object navigation. There are also options to change the colours and other settings
  • NVDA has a "Visual highlight" option. This puts a border around the current object with focus, which can highlight what NVDA is reading. The user guide describes the colours. Press NVDA+control+g to open NVDA’s settings, then control+tab to the "Vision" page.
  • NVDA has a "Speech viewer". This is a window which sits on top of other windows. It displays text which constantly refreshes to show what NVDA is reading. This is available from NVDA’s tools menu. Press NVDA+n to open the NVDA menu, then t for tools, then s for speech viewer.

While this section is quite short here, the full "Accessibility Testing with NVDA" package goes into much more detail. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Keyboard Navigation

Keyboard or mouse

Most blind users rely exclusively on the keyboard. Therefore, programs or web applications need to ensure there are keyboard functions for all features. In many cases, for instance, standard HTML on a web page, nothing additional is required. If explicitly defining mouse actions for a control in a program or onMouseOver events on the web, you will need to consider how keyboard users will access the feature.

NVDA will read information you hover over with the mouse. This feature is aimed at sighted, or low vision, mouse users, and should not be relied on to convey information to users who solely use the keyboard.

Opening a program or web page

Being able to navigate the PC with the keyboard is a useful skill to have in general. Microsoft have a large list of keystrokes which work in Windows. For the web, NVDA works with your chosen web browser (Firefox, Chrome, Edge, and most variants). We don’t recommend one over the other and believe it is important that pages work across browsers.

Load the browser and page to test you would like to text as you normally would. The main browsers accessible with the keyboard. Users will generally reach the address bar by pressing alt+d. Press alt+left arrow to move back to the previous page and alt+right arrow to move forward. Note these are browser commands rather than NVDA commands so will work with no screen reader running. There are many keyboard commands which are common across browsers.

Almost all NVDA commands can be identified through the use of the "NVDA Key". For instance, NVDA+t to read the title of the current window.

By default, NVDA will start reading when the page loads. If nothing is pressed, NVDA will read the entire page. Many users will stop this and explicitly navigate to specific information.

Navigation keys

Standard Windows navigation commands work to move through and read text:

  • Move back or forward by one character: left or right arrow.
  • Move back or forward by one word: control+left arrow or control+right arrow
  • Move back or forward by one paragraph: control+up arrow or control+down arrow

Virtual Buffer

On the web, NVDA takes the data from the web page and presents it in its own virtual buffer. This makes it efficient to quickly jump to various elements, however it does have several implications for sighted users:

Firstly, it means NVDA can not tell exactly how long any given line is. NVDA has a setting for "Maximum number of characters on one line" and similarly "Maximum lines per page". These control how many characters NVDA moves forward when down arrow is pressed, and how many lines down NVDA moves when page down is pressed.

For those using NVDA with the mouse, text selected on a web page with the mouse does appear to be selected visually. However, NVDA does not recognise it, and text selected with the mouse cannot be copied with control+c while NVDA is running. Selecting text with the keyboard (holding shift while navigating) and then copying with control+c does work.

Our "Accessibility Testing with NVDA" covers all these points in much greater detail. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Navigating Content with NVDA

Single Letter Navigation

While tab will move through the interactive elements on a web page (links, form fields, etc), these will skip the text and information around those elements. For this reason, tab is not usually the primary method of navigation screen reader users rely on. NVDA includes "Single Letter Navigation", letters which will jump to the next element of a certain type.

NVDA has single letter navigation keys to jump to headings, form fields, non-linked text, containers like tables, and more.

Some of the most commonly used of these are:
– h to jump to the next heading
– Numbers 1 to 9 to jump to the next heading at that level (2 for the next H2 heading, for instance)
– f to jump to the next form field, or e, b, x, r, c to jump to the next edit field, button, checkbox, radio button or combo box respectively
– L for list, t for table, comma to jump past the end of the current container (list or table)
– n for non-linked text, p for paragraph

Forms on the web

While reading, tab and shift+tab will jump to the next or previous interactive elements, which is useful for quickly getting to the most recently announced interactive elements.

When creating forms, it is important that elements such as edit boxes have an attached label. This ensures that NVDA correctly advises the user not only that there is an edit box, but also what the author expects to be typed into it.

Focus & Browse modes

We’ve previously noted that single letter navigation keys are handy to jump to various elements on a page. How then, do you type text into a form such as a search edit box? NVDA has two modes it uses:
– Browse mode is used for reading only. This allows those single letter navigation keys.
– Focus mode is used to edit documents, type text and submit information. Single letter navigation keys do not work in focus mode.

There are ways to jump between focus and browse modes manually, however NVDA will automatically switch as needed by default. Focus mode is activated when moving into a form field such as an edit or combo box (either by moving to it with tab, or clicking on it with the mouse). Browse mode is activated when moving out of a form field, such as tabbing to a link or when the form is submitted.

When navigating a form, press enter to activate either the current control, or the default control. For instance, in a form, pressing enter will often attempt to submit it, even if the focus is on another control.

To fill in a form on the web, the process is generally to read to the first form field then press tab (or shift+tab if you read past it), then fill in each form field and press tab to move to the next one, then enter to submit the form once done.

If there are any errors in the form the user tries to submit, it is important that errors are brought to the user’s attention in an accessible way.

Web applications

Applications on the web are becoming increasingly more complex. Many sites now implement their own single letter navigation. For instance, j and k are commonly used to jump to the previous or next post on social media. In order to use these site-specific keys, you can temporarily turn NVDA’s single letter navigation off for the current document with NVDA+shift+spacebar.

If you are finding this page useful, the full "Accessibility Testing with NVDA" package has even more information. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Working with Elements

Links

Links are the backbone of the web. It is important for links to have meaningful text, not simply "click here". NVDA has a command (NVDA+k) to report the destination of a link, however it is important that the name and the context of the link clearly indicate to the user where the link will take them.

Headings and Landmarks

Headings are not only visual indicators introducing different sections of content, they are vital for navigation. NVDA users can press h to jump to the next heading (of any level), or the numbers 1 to 9 to jump to the next heading at that level (Please don’t use nine levels of headings. If you think you have a valid use case for it, please let us know as I can’t think of one). Headings should always be hierarchical: H2 should be a subheading under H1, H3 under H2, etc. Many guides on headings, such as Mozilla’s recommend routines using no more than three levels of headings.

Landmarks are also used as logical separators. Consider the top handful of places your users might want to go on any given page (say up to half a dozen). Use Landmarks at these points. An NVDA user can then press d and shift+d to jump forward, or backwards through these to quickly get to important parts of the page.

Elements list

One important tool for screen reader users on the web is NVDA’s Elements list. This dialog lists various element types. Press NVDA+f7 to open the elements list.

When first opened, the elements list presents a list of all of the links on the current page, in chronological order, with the focus on the nearest link to the current point. The dialog can also display headings, form fields, buttons and landmarks. Users can either move to any presented element, or, for links, also activate the selected link.

When testing, the elements list is a useful tool to quickly present the structure of a page and ensure everything is logical, even out of context. This is also why it is important that links have meaningful text, not simply text like "click here".

Finding text

One way people find text on a web site is by searching. Activate NVDA’s find text function with NVDA+control+f. Because NVDA uses a virtual buffer to read the page, the inbuilt find function in most browsers does not work with NVDA. Users will also use the elements list to search for links or headings they anticipate should be on the page. In the elements list, pressing the first letter of the link or heading name will move through elements which begin with that letter.

Images and video

One of the most important aspects to remember when using images on the web is alt text. It is firstly what screen readers use to distinguish decorative images they can ignore (alt="") with images the user needs to be aware of (alt="describe the image here"). There are numerous guides to writing alt text online, but in general:

  • Keep it short
  • Consider why this image is important in the context of the page.
  • NVDA will tell you it is an image (or graphic), so "image of" is not required. However, if it is important, the fact it is a photograph, logo or painting may be worth adding.
  • Don’t duplicate text in the surrounding article. If the image is a photograph of a letter which is quoted verbatim in the text, then simply say it is a photograph of the letter which is included in the text. If there is important text conveyed in the image, it likely is worth presenting in the body of the page itself, as alt text may not be available to a user who isn’t using a screen reader.
  • End the alt text description with a period (full stop) if a pause after the description is useful in the context of the page.

Audio Description

When including a video, as with links, it is important to convey why it is included. In the video itself, use audio description to describe visual aspects which are important. If you are creating the video yourself, ideally incorporate this into the original video production.

Live Regions

Live regions are very useful. They can alert your users that something important has change. An error or that the user is about to be logged out, for instance. It is important to announce things without annoying your users.

Secure content

For many websites, users are required to create an account to fully access the functionality. For instance, users need a mail account before they can access a webmail site to send and receive messages. If using features such as "Captcha", it is important to ensure that the solution being used is accessible. Newer offerings such as Google’s latest ReCaptcha service, endeavour to do this without needing the user to identify traffic lights in an image, for instance. Where this is still required, this service provides an "Audio" option. While accessible, many users do find this annoying, and because of the way screen reader users interact with the web, they often seem to need to go through this "extra verification" more than other users. Please be aware of this when enforcing such checks.

Restricting actions while on a page, such as preventing users copying text, or opening the context menu, can also be problematic. It can be less accessible and fails WCAG 2.2, can introduce security risks, and may not prevent unauthorised copying by others in any case.

Consider purchasing the full "Accessibility Testing with NVDA" package, which has even more information. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Testing with a screen reader

What NVDA can’t test for

Not all accessibility issues can be tested for or discovered with a screen reader. Text which is very small, has very poor contrast, or which is partly obscured by an image all break requirements such as numerous WCAG success criteria. Such text, however, will generally still be able to be read by NVDA. That does not mean it is "accessible" to all users. Simply, that the problems with that text may not be experienced by a screen reader user.

NVDA is designed to follow web standards. According to these, images which are designed to be "decorative" and not add any important content to a page, should have an empty alt tag: alt="". If an image with important content has an empty alt tag like this, NVDA will treat it as decorative and ignore it, therefore it will not flag it as an error.

In fact, NVDA will generally not highlight any errors in content, context or presentation. It will endeavour to read everything, in some cases working around common errors. Or correctly reading something because the browser worked around the error. It is worth using other automated tools in conjunction with testing to flag such errors, and fixing them.

NVDA’s Strengths for testing?

NVDA is a tool aimed primarily at end users. NVDA is not specifically built with some of the features of accessibility testing apps. However, the fact that it is the tool used by blind people means that how something reads with NVDA is how a blind user navigating your content will read it. It should be noted that as with any tool, how one end user works with their screen reader will vary from how another user will – just as how one sighted user navigates your content will differ from how another sighted user navigates it. It is often worth having actual users test your content in a controlled environment in order to gauge reaction and ensure they are able to access all of the content.

Testing a site with NVDA

Testing with NVDA really comes down to:

  • What is a user coming to this page for?
  • How might a user navigate the page?
  • Can you get around the page with NVDA quickly, efficiently, and without missing key information?

The full "Accessibility Testing with NVDA" package, covers a number of ways of navigating what is there, and of looking for what is missing.

Reporting issues

Can you reproduce the issue after restarting or on other sites? What does your web accessibility tools report? Is this documented on the web? Can you reproduce with another browser or assistive technology? These will all help point towards the underlying cause. The vast majority of the time, the issue is with the page itself, and then to a lesser extend, a bug in a particular browser.

The full "Accessibility Testing with NVDA" package contains even more information on these topics. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Resources

The following are web accessibility resources primarily from other organisations. External links are for information only and are not endorsements from NV Access. It is worth considering multiple resources AND the reasoning for each recommendation.

NVDA References

Web Accessibility Resources:

These were found online. They are not endorsements from NV Access. Do evaluate multiple resources & consider the reasoning.

Accessibility Mailing lists

We hope you have found the information on this page useful. If so, please consider purchasing the full "Accessibility Testing with NVDA" package, which contains even more information on these topics. The full package includes more topics, expanded information, key takeaways and activities, printable reference sheets, extensive table of WCAG testing recommendations, and an exclusive NV Access Web A11y Ally badge. All sales support NV Access to continue to make NVDA itself free of charge to anyone around the world who can use it.

Thank you for your interest in improving web accessibility for everyone!