Web accessibility standards
Who sets the web accessibility standard?
The World Wide Web Consortium is the main international standards organization for the World Wide Web (abbreviated WWW Consortium or W3C). They have created a set of Web Content Accessibility Guidelines (WCAG) which are are recognised as the international standard for building accessible websites, and measuring web accessibility.
WCAG1.0 was a W3C recommendation on 5 May 1999, it had had three priority levels.
WCAG 1.0 consisted of 14 guidelines each of covered a basic theme of web accessibility.
- Provide equivalent alternatives to auditory and visual content
- Don’t rely on colour alone
- Correctly use html and style sheets
- Clarify natural language usage
- Create tables that transform gracefully
- Ensure that pages featuring new technologies transform gracefully
- Ensure user control of time sensitive content changes
- Ensure direct accessibility of embedded user interfaces
- Design for device independence
- User interim solutions
- Use W3Ctechnologies and guidelines
- Provide context and orientation information
- Provide clear navigation mechanisms
- Ensure that documents are clear and simple
Each guideline was broken up into a series of checkpoints. Each checkpoint was given a priority level between 1to 3 or also called Single A, Double A or Triple A compliance. Single A being the lowest level of compliance and triple A the highest.
Follow the link for information on WCAG 1.0.
WCAG 2.0 a W3C recommendation on 11 December 2008 bringing web accessibility guidance up to date with modern web development techniques.WCAG 2.0 consists of four principles which are broken down by additional guidelines.
Principle 1 Perceivable
Information and user interface components must be presentable to users in ways they can perceive.
- Guideline 1.1 Text alternatives: Provide text alternatives for any non-text content
- Guideline 1.2 Time based media: Provide alternatives for time based media
- Guideline 1.3 Adaptable: Create content that can be presented in different ways
- Guideline 1.4 Distinguishable: Make it easier for users to see and hear content
Principle 2 Operable
User interface components and navigation must be operable.
- Guideline 2.1 Keyboard Accessible: Make all functionality available from a keyboard
- Guideline 2.2 Enough Time: Provide users enough time to read and use content
- Guideline 2.3 Seizures: Do not design content in a way that is known to cause seizures
- Guideline 2.4 Navigable: Provide ways to help users navigate
Principle 3 Understandable
Information and the operation of the user interface must be understandable.
- Guideline 3.1 Readable: Make text content readable and understandable
- Guideline 3.2 Predictable: Make web pages appear and operate in predictable ways
- Guideline 3.3 Input Assistance: Help users avoid and correct mistakes
Principle 4 Robust
Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.
- Guideline 4.1 Compatible: Maximise compatibility with current and future user agents
Each guideline includes a series of success criteria which, like the WCAG 1.0 checkpoints, define rules for the accessibility of Web content, but which, unlike WCAG 1.0, are testable. The success criteria are assigned conformance levels (A, AA, AAA), in a similar way as WCAG 1.0 checkpoints.
Follow the link for more information on WCAG 2.0.