What is accessibility?

Developing an “accessible” website requires that all elements on the website can be accessed by anyone visiting your site. W3C director, Tim Berners-Lee, defines web accessibility as “access by everyone, regardless of disability.”

Disability Categories

There are 5 main disability categories. Understanding these categories will be helpful when developing your content:
  • Cognitive Learning
  • Auditory
  • Visual (including blind, low vision, and color blind)
  • Motor/Physical
  • Speech

Four Principles of Accessibility

The W3C website provides an overview of the Four Principles of Accessibility. These guidelines provide tips and suggestions to follow when creating a website


  • Provide text alternatives for non-text content. The easiest way to do this is using the “alt” tag.
  • Provide captions, transcripts, and other alternatives for multimedia.
  • Create content that can be presented in different ways without losing meaning.
  • Use methods that will make it easier for users to see and hear web content.


  • Create pages so all functionality is available from a keyboard.
  • Give users plenty of time to read and use content.
  • Do not use content that may trigger seizures. Avoid producing any content that violates spatial pattern thresholds.
  • Provide ways for users to find content, navigate and determine where they are within the site.


  • Make text content readable and understandable.
  • Make content appear and operate in predictable ways.
  • Help users avoid and correct mistakes. An example would be to hide any optional form fields.


  • Maximize compatibility with current and future user tools.
  • Avoid using any technologies that are not accessibility-supported when the technology is turned of or not supported.

Quick Tips for Accessibility

These Quick Tips provide a brief summary of the Web design concepts that support accessibility standards. For full guidelines and examples check out the Web Content Accessibility Guidelines.

  1. Images and animations: use the alt attribute to describe the function of each visual.
  2. Image maps: use the client-side map and text for hotspots.
  3. Multimedia: provide captioning and transcripts for audio, and descriptions of video.
  4. Hypertext links: use the text that makes sense when read out of context.
  5. Graphs and charts: Summarize graphs, charts, and tables using the longdesc attribute.
  6. Scripts, applets and plug-ins: provide alternative content in case active features are inaccessible or unsupported.
  7. Tables: make line-by-line reading sensible. Be sure to summarize each table and use appropriate titles and descriptions.
  8. Check your work: use validation tools to make sure web content is accessible.

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