The importance of accessibility in web applications

What is accessibility?

Accessibility is an approach to designing and building things that considers and accounts for people of all levels of ability. Out in the real-world evidence of accessibility can been seen in most public spaces. Public buildings are designed with ramps for people who can’t manage stairs. Elevator controls are marked with braille and a recorded voice announces the current floor for those who can’t see well enough. Signs use icons and symbols to help people that don’t or can’t read English. The common theme with all these examples is that we don’t assume everyone is the same, with the same abilities, and we make provisions to include as many people as reasonably possible.

So how do we apply principles of accessibility to the development of web applications? The same principles of inclusivity and consideration apply to the design of web applications as with their real-world counterparts. And as with their real-world counterparts the most effective application of accessibility begins at the start of the project at the design stage. While it is possible to retrofit some features of accessibility to an existing development, the same way you can add a ramp to a staircase in a real-world example, considering accessibility from the beginning results in more optimal outcomes. By considering the needs of people with a wide range of abilities, early design decisions can be made where access isn’t limited arbitrarily. Returning to our real-world example, a building could be designed without steps at the entrance, removing the need to add a ramp in later.

The assistive technology that supports the use of web applications has come on a long way in recent years. A significant proportion of computers and web-browsing software support numerous control interfaces out of the box. These include mouse, trackpad, keyboard, touchscreen and trackball. Also in common use is screen reading technology that converts onscreen text to synthesized speech or braille. For all these technologies to work properly the content and user interfaces of the web application must be built to support them. This means writing standards compliant mark-up (HTML) and using WAI-ARIA (Web Accessibility Initiative – Accessible Rich Internet Applications) attributes appropriately to describe the content semantically. This assists the reading technology in understanding the content presenting it to the user in the most useful and appropriate way.

Use of colour is another important part of accessible design. There are two common misuses of colour in web applications. The first is relying only on colour to convey information. Nearly 5% of all people have some degree of colour-blindness. They might struggle to understand the difference between a successful interaction and a failed interaction if the only indication of success is a change in colour. The second is using colours with insufficient contrast, particularly where text is displayed over a background colour or image. Even people without visual impairments struggle to read low contrast text and may miss an important interface feature or call-to-action.

Why is accessibility important?

If you have a message you need to communicate to as many people as possible then it doesn’t make sense to exclude people from your chosen medium of communication. Building a web application in accordance with principles of accessibility reduces the number of people who are excluded because of their ability. Furthermore, techniques that improve accessibility often improve general usability as well, which is of benefit to everyone. This is particularly true when it comes to building responsive applications designed to work on small touch screens like mobile phones. Another technical benefit is that Google assigns higher search results rank to websites that score well in accessibility tests.

Perhaps the most compelling reason for considering accessibility is that it is the law. The 2010 Equalities Act, and the 1995 Disability Discrimination Act that preceded it, makes it illegal to discriminate against disabled people when providing services. Discrimination is defined as not making reasonable adjustments to support everyone, regardless of (dis)ability. What constitutes reasonable adjustments is open to interpretation and will depend on the size of the organisation and the degree to which people will be affected by any failure to provide for them. There is an internationally recognised accessibility framework, the WCAG, that sets out three broad levels of accessibility provision (A, AA and AAA). For the majority of organisations meeting the requirements set out in level AA is usually sufficient.