Your website should meet the Web Content Accessibility Guidelines (WCAG) devised by W3C. There are three levels, with A being the absolute minimum accessibility standard and AAA being the highest.
It is generally agreed that meeting Level A is insufficient to ensure that most disabled users will have basic access. International legal policies have adopted level AA as their baseline, which requires meeting all the criteria in Levels A and AA.
The principles of accessibility
WCAG is based on 4 principles:
- Perceivable
- Operable
- Understandable
- Robust
Each principle relates in some way to making web content accessible. Focusing on principles emphasises the importance of thinking about how people interact with content in different ways.
Technical accessibility
Let’s use the analogy of a coin for a moment. On one side are the more technical aspects of accessibility, relating to the “Operable” and “Robust” principles. These ensure that content can be used and is compatible with different technologies, and would cover things like:
- Responsive design – your website needs to work on all devices of all sizes
- Cross-browser compatibility – your website doesn’t have to look identical in different browsers (e.g. Chrome, Edge, Firefox, Safari), but it should still be usable in all of them, even if they haven’t been updated to the latest version
- Supporting assistive technologies – such as keyboard navigation and screen readers
N.B: while not a part of WCAG, website performance is also important for a truly inclusive website and will consider the needs of people with limited data connectivity and older, less powerful devices (which is a lot of people). You can find out more about digital poverty from the Digital Poverty Alliance.
Content accessibility
On the other side of the coin, the “Perceivable” and “Understandable” principles directly address how people access and interpret content, and would include things like:
- Providing text alternatives for images, audio and video content (i.e. alternative text, captions and/or transcripts)
- Using simple, concise language and using hierarchical headings to organise content into sections and sub-sections
- Writing meaningful link text (not using “click here” or “read more”)
Although there is some crossover, generally the technical aspects of accessibility are something that a web developer will handle. Accessible content should be something that anyone can improve, and we’ve listed some resources below to help you get started.
Resources to help you improve content accessibility
We have written a guide to accessible content, which covers everything from writing alternative text for images to providing accessible instructions and how to use emojis.
Here are some additional resources:
Accessible writing
- Readability guidelines (Content Design London)
- Writing for web accessibility (W3C)
- Writing and designing for accessibility videos (Jon Gibbins)
Writing alternative (alt) text
- Alternative text (WebAIM)
- Improving alt text (BBC)
- Decorative images (W3C Web Accessibility Initiative)
Testing text contrast
A note about accessibility overlays
An “accessibility overlay” is a product that typically provides JavaScript code that you install on your website with the goal of improving accessibility. While they may seem like a simple fix, evidence shows that they are generally not sufficient to substantially improve website accessibility. Automated tools like these do not make a website compliant with international accessibility legislation – only about 20-30% of accessibility issues can be found without human intervention.
If you need help getting started with accessibility, get in touch for a chat.