What do we mean by accessibility?

What do we mean by accessibility?

What do we mean by accessibility?

what is accessibility

Accessibility is the practice of making your website usable by as many users as possible.
We’ve traditionally thought of this as only relevant to people with disabilities, but making a website more accessible can benefit other user groups as well.
People who use mobile devices, people who use low-speed Internet connections.
You can also think of accessibility as treating everyone the same, giving them an equal opportunity, regardless of their abilities or circumstances.
Just as it is wrong not to make buildings accessible to people in wheelchairs (modern public buildings often have wheelchair ramps or elevators); it is
also not right not to make our website accessible to visually impaired people.
We are all different, but we are all human and as such have equal human rights.
Making your website accessible is the right thing to do.
It is also part of the laws of some countries, and it opens up important markets where users would otherwise not be able to use your services or buy your products.
Building an accessible website benefits everyone:

  • Using primitive HTML

These style tags are deprecated in HTML5), not only improve accessibility, but also enhance search engine optimization, making your website easier to find.

  • Caring about accessibility shows good moral character, and it boosts your public image.
  • Other practices that improve accessibility will also make your site more usable by other groups,

For example, mobile phone users, users in low-speed network environments, and so on. In fact, everyone can benefit from these improvements.

  • Did we also mention that this is the law in some places as well?

What kinds of disabilities should we be concerned about?

People with disabilities are as diverse as people without disabilities, and they suffer from a variety of disabilities.
The key to the lesson here is to stop thinking about your own computer and the way you use the web, and start understanding how other people use the web—you are not your user.
Next, the main types of disabilities to consider, and some of the special tools (known as assistive technologies or ATs) they use to access web content.

Note: The World Health Organization’s “Disability and Health” fact sheet states that “more than 1 billion people, about 15 percent of the world’s population, live with
some form of disability” and that “between 110 million and Adults have significant difficulties with physical function.”

visually impaired

People with visual impairments include blind people, people with low levels of vision, and color blindness.
Many visually impaired people use screen magnifiers, either physical magnifiers or software zoom features.
Zooming is available in most browsers and operating systems today. Some users use a screen reader, which is software that reads digital text aloud.
Some examples of screen readers include:

  • Some are paid products such as JAWS (Windows) and Window Eyes (Windows).
  • Some are free products, such as NVDA (Windows), ChromeVox (Chrome, Windows and Mac OS X), and Orca (Linux).
  • Some are built into the operating system, such as VoiceOver (Mac OS X and iOS), Narrator (Microsoft Windows), ChromeVox (on Chrome OS), and TalkBack (Android).

It’s a good idea to familiarize yourself with a screen reader; you should also set up a screen reader and use it to the full (disk it) to understand how it works. See our cross-browser screen reader testing guide for more details on using them.
The video below also provides a simple example of what the experience is like.
According to statistics, the World Health Organization estimates that “285 million people worldwide are visually impaired: 39 million are blind and 246 million have low vision.” (See Vision Impairment and Blindness).
This is a large and important user base that is lost just because your website is not properly designed and coded-almost equal to the entire population of the United States.

hearing impaired

Also known as the hard of hearing or deaf, this group of people has either a low level of hearing or no hearing at all. These people use assistive technology (see Assistive Devices for People with Hearing, Speech, Speech, or Language Impairments), but do not have assistive technology specifically for computers/web pages.
However, there are now specialized technologies for converting text into audio content, ranging from converting simple text words to subtitles displayed with video. Later, there are articles that discuss these techniques.
Hearing-impaired people also represent a significant user group – “466 million people worldwide are hearing-impaired”, claims the World Health Organization’s Status of Deafness and Hearing Impairment report.

handicapped person

These individuals have mobility disabilities that may be due to purely physical problems (such as loss of limbs or paralysis), or neurological/genetic disorders that cause weakness or loss of control of limbs. Some people may have difficulty making the precise hand movements required to use a mouse, while others may be more severely affected and may be severely paralyzed to the point where they need to use a head pointer to interact with a computer.
This disability could also be due to old age rather than any specific trauma or condition, or it could be due to hardware limitations – some users may not have a mouse.
The way these disabilities often affect web development work is by requiring that the controls be accessible via the keyboard – we’ll discuss keyboard accessibility in a later article in this module, but it’s best to try accessing some websites just by using the keyboard and see What can you do. For example, can you use the Tab key to move between different controls on a web form? You can find more details about keyboard controls in our “Cross-Browser Testing Accessibility Using Native Keyboards” chapter.
According to statistics, a considerable number of people suffer from movement disorders. The Centers for Disease Control and Defense’s “Disability and Functioning (Outpatient Adults 18 and Over)” reports that 15.1 percent of adults in the United States have a functional disorder.

people with cognitive disabilities

Cognitive impairment encompasses a broad spectrum of disabilities, from those with the most limited abilities to those with intellectual disabilities who experience difficulties thinking and remembering as they age. This includes people with mental illnesses such as depression and schizophrenia. Also included are people with learning disabilities, such as those with dyslexia and those with attention deficit hyperactivity disorder. Importantly, despite many differences in clinical definitions of cognitive impairment, people associated with it experience the same type of functional problems. Such problems include difficulty understanding page content, difficulty remembering how to complete tasks, and confusion due to inconsistent web page layouts.
A good accessibility mechanism for people with cognitive disabilities includes:

  • Use a variety of methods to convey content, such as text to speech or video;
  • More understandable content, such as text written in a more common language;
  • focus on important content;
  • Minimize interruptions, such as unnecessary content or advertisements;
  • Consistent web page layout and navigation;
  • Similar elements, such as blue for unvisited underlined links and purple for visited ones;
  • Divide the process into more logical, necessary steps with progress indicators;
  • Make site authentication as simple as possible without compromising security; and
  • Make forms easy to complete, e.g. with clear error messages and easy error recovery.


  • Designing with cognitive accessibility will lead to good design practice. They will benefit everyone.
  • Many people with cognitive disabilities may also have physical disabilities. Websites must follow the W3C’s “Web Content Accessibility Guidelines” including the Cognitive Accessibility Guidelines.
  • The W3C’s Accessibility Task Force on Cognitive and Learning Disabilities produces web accessibility guidelines for people with cognitive disabilities.
  • WebAIM has an awareness web page that provides related information and resources.
  • The U.S. Centers for Disease Control estimates that as of 2018, one in four U.S. citizens has a disability, with cognitive impairment the most common ailment among young adults.
  • “Intellectual disability” is a new term for “mentally retarded” in the United States. In the UK, “mental disability” usually means “learning disability” or “learning difficulty”.

Implement accessibility in your projects

A popular myth about accessibility holds that accessibility is an expensive “additional feature” to implement on a project. This rumor may indeed be true, as long as any of the following situations are encountered:

  • You’re trying to “retrofit” accessibility for an existing website that has major accessibility issues.
  • You only start thinking about accessibility and related issues that are exposed at this point in the project.

However, the cost of making most content accessible is fairly small if you think about accessibility from the very beginning of your project.
Incorporate accessibility testing into your testing regime when planning your project, just as you would test any other important target audience, such as those targeting desktop or mobile browsers. Test early and often, ideally by running automated tests to identify missing functionality that is programmatically detectable (e.g. missing image alt text or bad link text – see Element Relationships and Context), and provide support for users with disabilities Groups do some testing to see if more complex website features are available to them. For example:

  • Will my date picker widget be usable by people with screen readers?
  • If the content is updated dynamically, will the visually impaired know?
  • Can my UI buttons be accessed using the keyboard and touch interface?

You can and should note potential problem areas in your content that need some work to become accessible, make sure you test them thoroughly and consider solutions/alternatives. Text content (as you’ll see in the next article) is relatively easy, but what about multimedia content and funky 3D graphics? You should look at your project budget and consider what solutions you can use to make this type of content accessible. Transcribing all multimedia content is an option, which of course can be costly.
Also, be realistic. “100% accessibility” is an unattainable ideal – you’re always going to have some kind of edge case where a user finds something hard to use – but you should do what you can. If you plan to include a funky 3D pie chart rendered using WebGL, you might want to include a data table as well, as an accessible alternative representation of the data. Or, you might just include the table and get rid of the 3D pie chart – this makes the table accessible to everyone, faster to write, less CPU-intensive at runtime, and easier to maintain.
On the other hand, if you’re presenting interesting 3D art on a gallery website, it’s unreasonable to expect every piece of art to be perfectly accessible to the visually impaired since it’s a completely visual medium after all.
To show that you care about and consider accessibility, post an accessibility statement on your website detailing your policy on accessibility and the steps you are taking to make the site accessible. If someone does report an accessibility issue with your site, start a dialogue with them, be compassionate, and take reasonable steps to try to fix the problem.

  • Think about accessibility from the very beginning of your project, and test it early. Just like any other bug, the later an accessibility problem is discovered, the more expensive it will be to fix.
  • Remember that many accessibility best practices benefit everyone, not just those with disabilities. For example, primitive markup is not only good for screen readers, it also makes for faster loading and performance, so it’s better for everyone, especially those on mobile devices and/or with slow internet connections.
  • Post an accessibility statement on your site and reach out to people who have problems.

Accessibility Guidelines and Laws

There are many checklists and sets of guidelines available for accessibility-based testing, and at first glance, these guidelines can seem daunting. Our advice is to familiarize yourself with the basic areas you need to pay attention to, as well as understanding the high-level structure of the guidelines that are most relevant to you.

  • First, the W3C publishes a large and detailed document containing very precise, technology-agnostic accessibility conformance standards. These are called Web Content Accessibility Guidelines (WCAG), and they are by no means short reads. These standards fall into four broad categories that specify how to make implementations perceivable, operable, understandable, and robust. The best place to get a brief introduction and start learning is at a glance. There is no need to study WCAG by heart – pay attention to the main areas of concern and use a variety of techniques and tools to highlight any areas that are not WCAG compliant (more on that below).
  • Your country may also have specific legislation stipulating that websites serving its population must be accessible – for example, Section 508 of the US Rehabilitation Act, Germany’s Federal Act on Accessible Information Technology, the UK’s Equality Act, Italy’s The Accessibility Act, Australia’s Disability Discrimination Act, etc.

So while WCAG is a set of guidelines, your country may have laws regarding web accessibility, or at least accessibility to services provided by the public (including websites, television, physical spaces, etc.). It’s a good idea to find out your laws. If you don’t make an effort to check that your content is accessible, you could get into legal trouble if someone with duality complains about it.
This sounds serious, but as stated above, you just need to consider accessibility a major priority in your web development practice. If in doubt, consult a qualified attorney. We won’t give more advice than this because we are not lawyers.

Accessibility API

Web browsers use special accessibility APIs (provided by the underlying operating system) that expose information useful to assistive technologies (ATS) – ATS mostly tend to use primitive information, so this information does not include style information or javascript the content of the class. This information is structured in an information tree called the accessibility tree.
Different operating systems have different accessibility APIs:

  • Windows: MSAA/IAccessible, UIAExpress, IAccessible2
  • Mac OS X: NSAccessibility
  • Linux: AT-SPI
  • Android: Accessibility framework
  • iOS: UIAccessibility

If the native semantic information provided by HTML elements in a web application fails, that information can be supplemented with features of the WAI-ARIA specification that add semantic information to the accessibility tree to improve accessibility. Learn more about WAI-ARIA in the WAI-ARIA basics article.


This article should give you a useful high-level overview of accessibility, show you why it’s important, and examine how you can incorporate it into your workflow. Now, you should also be eager to understand the implementation details that make your site accessible, and we’ll start in the next section with why HTML is a good foundation for accessibility.

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