Accessibility tooling and assistive technology

Let's have a look at the tools can make use of when implementing accessibile websites and fixing accessibility issues.

Your content should make logical sense in its source order — you can always place it where you want using CSS later on, but you should get the source order right to start with.

As a test, you can turn off a site's CSS and see how understandable it is without it. You could do this manually by just removing the CSS from your code, but the easiest way is to use browser features, for example:

• Firefox: Select View > Page Style > No Style from the main menu.
• Safari: Select Develop > Disable Styles from the main menu (to enable the Develop menu, choose Safari > Preferences > Advanced > Show Develop menu in menu bar).
• Chrome: Install the Web Developer Toolbar extension, then restart the browser. Click the gear icon that will appear, then select CSS > Disable All Styles.
• Edge: Select View > Style > No Style from the main menu.

When choosing a color scheme for your website, you should make sure that the text (foreground) color contrasts well with the background color. Your design might look cool, but it is no good if people with visual impairments like color blindness can't read your content. Use a tool like WebAIM's Color Contrast Checker to check whether your scheme is contrasting enough.

Another tip is to not rely on color alone for signposts/information, as this will be no good for those who can't see the color. Instead of marking required form fields in red, for example, mark them with an asterisk and in red.

There are a number of auditing tools available that you can feed your web pages into. They will look over them and return a list of accessibility issues present on the page. Let's look at an example, using Wave, an online accessibility testing tool that accepts a web address and returns an annotated view of that page with accessibility problems highlighted.

1. Go to the Wave homepage.
2. Enter the URL of our bad-semantics.html example into the text input box near the top of the page. Then press enter or click/tap the arrow at the far right edge of the input box.
3. The site should respond with a description of the accessibility problems. Click the icons displayed to see more information about each of the issues identified by Wave's evaluation.

Other auditing tools that are worth checking out:

• Firefox Accessibility Inspector
• ANDI bookmarklet
• Google Lighthouse accessibility audits

Deque's aXe tool goes a bit further than the auditing tools we mentioned above. Like the others, it checks pages and returns accessibility errors. Its most immediately useful form is probably the browser extensions:

• aXe for Chrome
• aXe for Firefox

These add an accessibility tab to the browser developer tools. For example, we installed the Firefox version, then used it to audit our bad-table.html example. We got the following results:

aXe is also installable using npm, and can be integrated with task runners like Grunt and Gulp, automation frameworks like Selenium and Cucumber, unit testing frameworks like Jasmine, and more besides (again, see the main aXe page for details).

It is definitely worth testing with a screen reader to get used to how severely visually impaired people use the Web. There are a number of screen readers available:

• Some are paid-for commercial products, like JAWS (Windows).
• Some are free products, like NVDA (Windows), ChromeVox (Chrome, Windows, and macOS), and Orca (Linux).
• Some are built into the operating system, like VoiceOver (macOS and iOS), ChromeVox (on Chromebooks), and TalkBack (Android).

Generally, screen readers are separate apps that run on the host operating system and can read not only web pages, but text in other apps as well. This is not always the case (ChromeVox is a browser extension), but usually, screen readers tend to act in slightly different ways and have different controls, so you'll have to consult the documentation for your chosen screen reader to get all the details — saying that, they all work in basically the same sort of way.

Let's go through some tests with a couple of different screen readers to give you a general idea of how they work and how to test with them.

VoiceOver (VO) comes free with your Mac/iPhone/iPad, so it's useful for testing on desktop/mobile if you use Apple products. We'll be testing it on macOS on a MacBook Pro.

To turn it on, press Cmd + F5. If you've not used VO before, you will be given a welcome screen where you can choose to start VO or not, and run through a rather useful tutorial to learn how to use it. To turn it off again, press Cmd + F5 again.

When VO is on, the display will look mostly the same, but you'll see a black box at the bottom left of the screen that contains information on what VO currently has selected. The current selection will also be highlighted, with a black border — this highlight is known as the VO cursor.

To use VO, you will make a lot of use of the "VO modifier" — this is a key or key combination that you need to press in addition to the actual VO keyboard shortcuts to get them to work. Using a modifier like this is common with screen readers, to enable them to keep their commands from clashing with other commands. In the case of VO, the modifier can either be CapsLock, or Ctrl + Option.

VO has many keyboard commands, and we won't list them all here. The basic ones you'll need for web page testing are in the following table. In the keyboard shortcuts, "VO" means "the VoiceOver modifier".

This seems like a lot of commands, but it isn't so bad when you get used to it, and VO regularly gives you reminders of what commands to use in certain places. Have a play with VO now; you can then go on to play with some of our examples in the Screen reader testing section.

NVDA is Windows-only, and you'll need to install it.

1. Download it from nvaccess.org. You can choose whether to make a donation or download it for free; you'll also need to give them your email address before you can download it.
2. Once downloaded, install it — you double-click the installer, accept the license and follow the prompts.
3. To start NVDA, double-click on the program file/shortcut, or use the keyboard shortcut Ctrl + Alt + N. You'll see the NVDA welcome dialog when you start it. Here you can choose from a couple of options, then press the OK button to get going.

NVDA will now be active on your computer.

To use NVDA, you will make a lot of use of the "NVDA modifier" — this is a key that you need to press in addition to the actual NVDA keyboard shortcuts to get them to work. Using a modifier like this is common with screen readers, to enable them to keep their commands from clashing with other commands. In the case of NVDA, the modifier can either be Insert (the default), or CapsLock (can be chosen by checking the first checkbox in the NVDA welcome dialog before pressing OK).

NVDA has many keyboard commands, and we won't list them all here. The basic ones you'll need for web page testing are in the following table. In the keyboard shortcuts, "NVDA" means "the NVDA modifier".

Now you've gotten used to using a screen reader, we'd like you to use it to do some quick accessibility tests, to get an idea of how screen readers deal with good and bad webpage features:

• Look at good-semantics.html, and note how the headers are found by the screen reader and available to use for navigation. Now look at bad-semantics.html, and note how the screen reader gets none of this information. Imagine how annoying this would be when trying to navigate a really long page of text.
• Look at good-links.html, and note how they make sense when viewed out of context. This is not the case with bad-links.html — they are all just "click here".
• Look at good-form.html, and note how the form inputs are described using their labels because we've used <label> elements properly. In bad-form.html, they get an unhelpful label along the lines of "blank".
• Look at our punk-bands-complete.html example, and see how the screen reader is able to associate columns and rows of content and read them out all together because we've defined headers properly. In bad-table.html, none of the cells can be associated at all. Note that NVDA seems to behave slightly strangely when you've only got a single table on a page; you could try WebAIM's table test page instead.
• Have a look at the WAI-ARIA live regions example we saw earlier, and note how the screen reader will keep reading out the constantly updating section as it updates.

As mentioned above, you can't rely on automated tools alone for determining accessibility problems on your site. It is recommended that when you draw up your testing plan, you should include some accessibility user groups if at all possible. Try to get some screen reader users involved, some keyboard-only users, some non-hearing users, and perhaps other groups too, as suits your requirements.

Many other assistive technology types exist, such as:

• Large text or braille keyboards.
• Alternative pointing devices such as trackballs, joysticks, and touchpads.
• Screen magnifiers.
• Voice recognition software.
• Switch controls.

The following list provides a checklist for you to follow to make sure you've carried out the recommended accessibility testing for your project:

1. Make sure your HTML is as semantically correct as possible. Validating it is a good start, as is using an auditing tool.
2. Check that your content makes sense when the CSS is turned off.
3. Make sure your functionality is keyboard accessible (see UI controls for more details). Test using Tab, Return/Enter, etc.
4. Make sure your non-text content has text alternatives. An auditing tool is good for catching such problems.
5. Make sure your site's color contrast is acceptable, using a suitable checking tool.
6. Make sure hidden content is visible by screen readers.
7. Make sure that functionality is usable without JavaScript wherever possible.
8. Use ARIA to improve accessibility where appropriate.
9. Run your site through an auditing tool.
10. Test it with a screen reader.
11. Include an accessibility policy/statement somewhere findable on your site to say what you did.

Hopefully this article has given you an idea of the kinds of tools you can use to help fix accessibility issues, the assistive technology used by people with disabilities to help access the web.

In the next article we'll look how to write accessible HTML.

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