Web Accessibility

Updated: 03 September 2023

Notes from the W3C’s Introduction to Web Accessibility Course on EdX

What is Web Accessibility

Technology Enabling People with Disabilities

Before we can understand and learn the standards it’s useful to understand how people with disabilities use the web

Generally, applications need to work with people who are unable to interact with screens in traditional ways like using a mouse, or even for users who are visually impaired using tools like screen readers

Screen Readers

Some important aspects for working with screen readers are:

  1. Good page titles
  2. Well structured headings
  3. Clear link text
  4. Alt text for images
  5. Using lists

Other than screen readers users can also use tools like digital braille display

Non-Screen Reader Users

Screen readers aren’t the only way that users interact with screens, for example users who are deaf and sighted may need text in place of audio content or users who users who have low vision or partial hearing and may need ways to use different assistive technologies to make content more accessible to them

Text Wrapping

Text wrapping is important to be aware of for users who usually have low vision, dyslexia, or other related conditions sometimes use text zoom to make it easier to read content on a page

For these users it’s important to make sure that text wraps appropriately so that these users don’t need to scroll both horizontally and vertically to read content and are able to interact with text in a single scroll direction

Scope of Accessibility

Web Accessibility means that technologies are designed so people with disabilities can use them. This means that people can:

  • Perceive, understand, navigate, and interact with the web
  • Contribute to the web

Accessibility encompasses different needs, such as:

  • Auditory
  • Cognitive
  • Neurological
  • Physical
  • Speech
  • Visual

Additionally, accessibility also overlaps with things like inclusive and universal design which extend to areas like:

  • Geographic Location
  • Economic Circumstances
  • Education
  • Language
  • Age
  • Gender

Furthermore, most of the things done to enhance accessibility can also benefit users without disabilities


It’s also important to be aware that users of different disabilities may have totally opposing accessibility needs and these need to be considered individually. Users with disabilities that are categorized similarly may have opposing needs. For example blind users using a screen reader may have totally different needs to a user with low vision which may require larger font sizes

Benefit to Others

Web accessibility also benefits people without disabilities, for example:

  • Devices with different input modes
  • Older people with changing abilities
  • People with “temporary disabilities” e.g. a broken arm
  • People with “situational limitations” like in bright light
  • People with a slow or limited internet connection

Accessible Audio and Video Media

When making audio and video available for deaf or hard of hearing users we add things like transcript or captions

These can benefit other users in ways like:

  • Transcripts can be skimmed or read which can be useful for users to get a summary of content. The can also be used without needing to download a video or can be used offline or printed
  • Captions can be useful in loud environments or in environments where a user can’t use sound. They’re also useful for users learning a new language or users using captions to help focus or retain information

Accessibility Considerations

Some considerations which are important for accessibility are:

  1. Captions or transcripts
  2. Colour contrast
  3. Voice recognition
  4. Text to speech
  5. Good layout
  6. Notifications and feedback, clear error messaged
  7. Appropriately sized targets
  8. Customization
  9. Clear language
  10. Keyboard navigation