What is web accessibility?
According to the United States Census Bureau there are close to 60 million Americans with disabilities. People with hearing, vision, cognitive or motor impairments often need assistive technologies to help them navigate the web. Blind people for instance use the internet with the help of screen readers that read the text of a web page to them. Web accessibility is the practice to help both people with impairments as well as assistive technologies to better understand the content of a webpage.
As web developers one of our main goals these days is to make sure websites can easily be viewed on a mobile device. We all have come across websites which were not optimised for mobile, e.g. the page content may have been wrapped inside a
<table> with a fixed width for layout puroposes. In this case viewing the web page on a small mobile screen can be difficult. However, optimising websites for mobile should not be our only concern of accessibility. It is important that the internet is accessible for people with disabilities as well. Web development with accessibility in mind is crucial in order to guarantee that all users can fully access the content of a website.
Web accessibility guidelines
In order to streamline the efforts of making the web accessible to all users the Web Accessibility Initiative (WAI) published the Web Content Accessibility Guidelines (WCAG), which categorises the accessibility requirements into four principles, referred to as POUR: Perceivable, Operable, Understandable, Robust. Each section of the document points to other external documents such as How To Meet the WCAG 2, a quick reference guide with more detailed information. The filters in the left sidebar of this online document are useful to quickly find requirements of a particular kind or compliance level.
How to meet the requirements
The WACG 2.0 guidelines outline 3 levels of conformance: A, AA and AAA. Whether or not compliance is legally required (or which level of compliance) depends on government regulations, which are outlined in the Section 508 of the Rehabilitation Act of 1973. At Boyle Software we try to conform at least with level A of the WCAG 2.0 and with level AA if the project allows us to also have certain control over the design.
Level A compliance examples:
- All non text-content has a text alternative.
- Use ARIA landmarks to identify content.
- All functionality on a web page must also be available from a keyboard.
Level AA compliance examples:
- Visual presentation of text and images of text has a contrast ratio of at least 4.5:1.
- Text can be resized without assistive technology up to 200 percent without loss of content or functionality.
- Headings and labels describe topic or purpose.
Testing for compliance can be done both in a manual and in an automated way and usually requires both. At Boyle Software we use a command-line tool called pa11y to continually check the project for accessibility compliance during development.
There is also a desktop app called Koa11y which allows to test websites against a particular conformance level.
Boyle Software takes web accessibility seriously. Making sure that web content is accessible and operable to users with disabilities can improve the user experience for everyone. We are happy to work with clients on achieving the level of web accessibility compliance required for their website.
- Guidelines: Web Content Accessibility Guidelines (WCAG)
- Checklist: WebAIM checklist
- Examples: ARIA Landmark
- Tool: Online accessibility check
- Tool: axE accessibility check Chrome extension
- Development: Web accessibility fundamentals for developers
- Course: Free Udacity web accessibility course
- Design: Universal design