Introduction to WCAG

The Web Content Accessibility Guidelines (WCAG) are developed through the W3C process in cooperation with individuals and organizations globally to provide consensus guidance on accessible web content. First introduced in 1999, WCAG 1.0 aimed to help web content developers create sites that better met the needs of people with disabilities. Current guidance comes from the more comprehensive WCAG 2.1 published in 2018, which expands Web Content Accessibility Guidelines to cover more types of disabilities, applies to new technologies, and increases conformance expectations.

WCAG sets out recommendations and success criteria for making web content accessible for a wider range of situations faced by people with disabilities. This includes users with visual, auditory, mobility, speech, cognitive and neurological disabilities who access content via desktops, laptops, tablets, mobile devices, legacy browsers and assistive technologies like screen readers.

Principles of Accessible Web Design in WCAG

The Web Content Accessibility Guidelines framework revolves around 4 core principles often abbreviated as POUR:

  1. Perceivable – Users can perceive/sense the information being presented
  2. Operable – Components and navigation work for all users
  3. Understandable – Content appears clear and logically structured
  4. Robust – Interpretation remains clear across various access methods

Each principle establishes guidelines for web development teams to follow so that content reliably meets that accessibility goal. Under each guideline, WCAG provides specific, testable success criteria mapped to 3 levels of conformance from A (basic) to AAA (highest). Most legislation and policies require organizations to meet level AA or ATAG 2.0 conformance.

Web Content Accessibility Guidelines Criteria

The Web Content Accessibility Guidelines outlines 26 specific guidelines across the 4 principles mentioned above. A few key criteria within the WCAG 2.1 guidelines include:

  • Non-text elements like images, graphics and multimedia have text alternatives (“alt text”) describing the purpose and content
  • Captions and transcripts accompanying pre-recorded audio content
  • Adaptable information architecture through correct heading hierarchy and site navigation
  • Sufficient color contrast between foreground and background elements
  • Logical focus order allowing navigation via keyboard only
  • Avoiding content that flashes rapidly between 2 and 55 times per second
  • Multi-modal representations of concepts through illustrations paired with written descriptions

Each guideline has around 2 to 5 related success criteria that become more complex as conformance levels increase. For the full details, see the W3C’s Web Content Accessibility Guidelines (WCAG) Overview resource.

Validating Conformance to Web Content Accessibility Guidelines

The Web Content Accessibility Guidelines are designed to be technology-neutral and testable against web content. Validation of conformance with WCAG 2.1 can happen through a combination human and automated testing methods such as:

  • Code validation against standards with tools like WAVE and Axe
  • Screen reader testing with NVDA, VoiceOver and TalkBack
  • Contrast checker tools to analyze color combinations
  • Browser validation through keyboard navigation only
  • Zooming content to 200% and 400%
  • Disabling css/stylesheets to check structured content
  • Automated accessibility scripting tools

By leveraging these evaluation methods, organizations can systematically confirm compliance with Web Content Accessibility Guidelines across their sites. Ongoing monitoring rather than one-time audits are recommended to account for new content and functionality. Resources like WebAIM provide expanded guidance on accessibility testing for WCAG conformance.

Going Beyond Minimum Compliance

While the Web Content Accessibility Guidelines aim to capture a wide range of user accessibility needs, meeting the 2.1 AA standards should be viewed as the starting point rather than the end goal. Even AAA conformance does not equate to a smooth, positive experience for all people with disabilities.

Automated testing and assistive technology simulations provide insights, but genuine user research interviews allow deeper understanding of pain points. Conduct ongoing testing with actual users with visual, hearing, motor and cognitive impairments to guide design decisions. Building a feedback loop with the disability community ensures you address nagging issues that guidelines have not yet incorporated.

Prioritizing accessibility pays dividends through better user experience for all audiences, reduced maintenance costs from proper markup, and improved brand reputation. Review the full WCAG 2.1 framework, then leverage the advice in this article to evaluate and improve your site’s current level of conformance. Focusing on the principles of perceivable, operable, understandable and robust content allows more users to access your information and services.

Have you used Web Content Accessibility Guidelines in your organization? What successes and challenges have you encountered? Please share your thoughts in the comments below!