WCAG 2.1 Guidelines Explained
A history lesson: where did the website accessibility guidelines come from and what’s in them?
- 1995: The first web accessibility guidelines were compiled by Gregg Vanderheiden shortly after the 1995 Chicago WWW II Conference.
- 1998: University of Wisconsin–Madison compiled the Unified Web Site Accessibility Guidelines.
- 1999: they formed the basis for WCAG 1.0.
WCAG 1.0. were focused on HTML and web pages.
- 14 guidelines.
- 65 checkpoints.
- Each with a priority level: A, AA. AAA.
A Compliance: the guidelines must be satisfied otherwise it will be impossible for one or more groups to access the Web content.
AA Compliance: should be satisfied, otherwise some groups will find it difficult to access the Web content.
AAA Compliance: may be satisfied: to make it easier for some groups to access the Web content.
14 WCAG 1 Guidelines
- Guideline 1: Provide equivalent alternatives to auditory and visual content.
- Guideline 2: Don’t rely on colour alone.
- Guideline 3: Use markup and style sheets, and do so properly.
- Guideline 4: Clarify natural language usage.
- Guideline 5: Create tables that transform gracefully.
- Guideline 6: Ensure that pages featuring new technologies transform gracefully.
- Guideline 7: Ensure user control of time-sensitive content changes.
- Guideline 8: Ensure direct accessibility of embedded user interfaces.
- Guideline 9: Design for device independence.
- Guideline 10: Use interim solutions.
- Guideline 11: Use W3C technologies and guidelines.
- Guideline 12: Provide context and orientation information.
- Guideline 13: Provide clear navigation mechanisms.
- Guideline 14: Ensure that documents are clear and simple.
WCAG 2 – Published 2008
Not just websites, but also PDF, Google Docs, Spreadsheets, e-Books… and other ‘digital assets’.
WCAG 2.1 – Published 2018
- WCAG 2.1 does not deprecate or supersede WCAG 2.0.
- The differences between WCAG 2.0 and 2.1 are mostly related to the use of tablets and mobile devices.
- They are designed to make content more accessible to a wider range of people, including accommodations for blindness and low vision.
WCAG 2.1 Based on 4 Principles
What do the principles mean?
WCAG speak: information and user interface components must be presentable to users in ways they can perceive.
Jim speak: the site visitor must be able to recognise that the content exists. For example, by being able to see it, hear it or touch it.
- WCAG speak: user interface components and navigation must be operable.
- Jim speak: the site visitor must be able to navigate around the site and use the features and functions presented.
- WCAG speak: information and the operation of user interfaces must be understandable.
- Jim speak: not only should visitors be able to recognise the existence of the content and be able to interact with it, but they must also be able to understand it.
- WCAG speak: content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.
- Jim speak: it must be possible to access the content using everything from a text-only web browser to the latest Firefox browser. And everything in between, including screen readers and all the different brands and versions of browsers now available.
Each Principle Has A Set Of Guidelines
1. Perceivable: the guidelines relate to:
- Text alternatives for non-text content.
- Captions and other alternatives for multimedia.
- Content can be presented in different ways, including by assistive technologies, without losing meaning.
Operable: the guideline Relate To:
- Ensuring functionality is available for keyboard users.
- Giving users enough time to read and use content.
- Avoiding content that causes seizures or physical reactions.
- Help users navigate and find content.
- Making it easier to use inputs other than by keyboard.
Understandable: the guideline Relate To:
- Make text readable and understandable.
- Make content appear and operate in predictable ways.
- Help users avoid and correct mistakes.
Robust: the guideline Relate To:
- Maximising compatibility with current and future user tools.
- For example, by using valid code.
For Each Principle
There are guidelines – these are the basic goals that authors should work toward in order to make content more accessible.
And For Each Guideline
Ther are ‘testable success criteria’.
- Three levels of conformance are defined as: A (lowest), AA, and AAA (highest).
- Techniques and examples are provided for meeting those criteria.
- All ‘success criteria’ apply to mobile platforms as well as desktop platforms.
- However, the techniques sections does not yet fully cover mobile techniques.