Understand web Accessibility will be a serie of 10 short articles. The goal here is to share some short insights about web accessibility, one by day (not the week-end), especially for developers. Because Accessibility awareness is so important... Hope you will enjoy it!

The beggining

The Web Content Accessibility Guidelines was reated in 1999, by the Web Accessibility Initiative (WAI).
WCAG defines how to make web content more accessible to people with disabilities.

The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect.
__Tim Berners-Lee, W3C Director and inventor of the World Wide Web

The 4 principles

So, to provide an equal digital access for everyone on the planet, WCAG members started to think about the basic needs. Whatever the disability is, anybody on the web should be able to:

• perceive,

• understand,

• navigate,

• and interact with the Web (contribute to the Web).

A short example...

For each principle, you will find some success criteria associated. Let's take a simple example:
To be sure everything is perceivable, even for blind users, the first criterion (1.1.1) is: "All non-text content that is presented to the user has a text alternative that serves the equivalent purpose...".
It means that if you have a star button icon to add a product in your favorites without any alternative text, people using assistive technologies (or some elderly people or with cognitive disabilities) will not be able to "see" or "hear" it correctly.

The 3 Accessibility levels

What is generally mandatory is to be compliant at the level AA of the WCAG 2.1 (in 2023), so around 50 success criterias should be aimed:

A: Essential

The most basic level. If this isn't met, assistive technology may not be able to read, understand, or fully operate the page or view (30 criterias).

AA: Ideal Support

Required for multiple government and public body websites. Companies strives for AA compliance. Making a website legally accessible typically means achieving these WCAG AA standards. This level includes all Level A and AA requirements (20 criterias), so around 50 success criterias to meet.

AAA: Specialized Support

Includes a higher, more strict set of benchmarks, like: All pre recorded audio content should be provided with sign language interpretation. This is typically reserved for parts of websites and web apps that serve a specialized audience (28 criterias).

Read more:
https://userway.org/blog/what-are-wcag-2-0-a-aa-and-aaa/