Web Content Accessibility Guidelines (WCAG)

The Web Content Accessibility Guidelines (WCAG) are a set of guidelines for making digital content more accessible for people with disabilities.

Looking for an easy way to get started with WCAG?

What does WCAG mean for you as an app developer?#

Don't be fooled by the name, these guidelines also apply to apps. But not all of them. Which guidelines apply to your specific situation depends on where in the world your app is available. The way in which accessibility is guaranteed and mandated by the government differs considerably per region. The specific way the WCAG is incorporated into local law determines what you need to do to make your app comply. Following are the most well-known implementations of the WCAG. Followed by an explanation of the WCAG structure and an overview of all the guidelines.

WCAG structure#

Version 2.1 of the WCAG consists of 4 principles, 13 guidelines and 78 success criteria. The success criteria are divided into three levels of conformance.

1. Level A: sets a minimum level of accessibility. There are 30 criteria to meet. If your app does not conform with level A, it may have serious accessibility issues. This will likely prevent users with disabilities from being able to use it.

2. Level AA: sets a strong level of accessibility. There are 20 criteria to meet, plus 30 criteria at level A. When your app conforms to level AA, users with disabilities will likely be able to use it.

3. Level AAA: sets the highest level of accessibility. There are 28 criteria to meet, plus 50 criteria at level A and AA. Note: it's not possible to satisfy level AAA for all content.

We recommend meeting at least level AA, and level AAA where possible.

The image below shows the structure of the WCAG 2.1. Criteria marked with a star (*) are excluded in EN 301 549.

Guidance#

The list below contains links to our guides for each principle, guideline and success criterion.

• Principle 1 - Perceivable

  • Guideline 1.1 - Text Alternatives

    • Success Criterion 1.1.1 - Non-text Content - Level A

  • Guideline 1.2 - Time-based Media

    • Success Criterion 1.2.1 - Audio-only and Video-only (Prerecorded) - Level A

    • Success Criterion 1.2.2 - Captions (Prerecorded) - Level A

    • Success Criterion 1.2.3 - Audio Description or Media Alternative (Prerecorded) - Level A

    • Success Criterion 1.2.4 - Captions (Live) - Level AA

    • Success Criterion 1.2.5 - Audio Description (Prerecorded) - Level AA

    • Success Criterion 1.2.6 - Sign Language (Prerecorded) - Level AAA

    • Success Criterion 1.2.7 - Extended Audio Description (Prerecorded) - Level AAA

    • Success Criterion 1.2.8 - Media Alternative (Prerecorded) - Level AAA

    • Success Criterion 1.2.9 - Audio-only (Live) - Level AAA

  • Guideline 1.3 - Adaptable

    • Success Criterion 1.3.1 - Info and Relationships - Level A

    • Success Criterion 1.3.2 - Meaningful Sequence - Level A

    • Success Criterion 1.3.3 - Sensory Characteristics - Level A

    • Success Criterion 1.3.4 - Orientation - Level AA

    • Success Criterion 1.3.5 - Identify Input Purpose - Level AA

    • Success Criterion 1.3.6 - Identify Purpose - Level AA

  • Guideline 1.4 - Distinguishable

    • Success Criterion 1.4.1 - Use of Color - Level A

    • Success Criterion 1.4.2 - Audio Control - Level A

    • Success Criterion 1.4.3 - Contrast (Minimum) - Level AA

    • Success Criterion 1.4.4 - Resize text - Level AA

    • Success Criterion 1.4.5 - Images of Text - Level AA

    • Success Criterion 1.4.6 - Contrast (Enhanced) - Level AAA

    • Success Criterion 1.4.7 - Low or No Background Audio - Level AAA

    • Success Criterion 1.4.8 - Visual Presentation - Level AAA

    • Success Criterion 1.4.9 - Images of Text (No Exception) - Level AAA

    • Success Criterion 1.4.10 - Reflow - Level AA

    • Success Criterion 1.4.11 - Non-text Contrast - Level AA

    • Success Criterion 1.4.12 - Text Spacing - Level AA

    • Success Criterion 1.4.13 - Content on Hover or Focus - Level AA

• Principle 2 - Operable

  • Guideline 2.1 - Keyboard Accessible

    • Success Criterion 2.1.1 - Keyboard - Level A

    • Success Criterion 2.1.2 - No Keyboard Trap - Level A

    • Success Criterion 2.1.3 - Keyboard (No Exception) - Level AAA

    • Success Criterion 2.1.4 - Character Key Shortcuts - Level A

  • Guideline 2.2 - Enough Time

    • Success Criterion 2.2.1 - Timing Adjustable - Level A

    • Success Criterion 2.2.2 - Pause, Stop, Hide - Level A

    • Success Criterion 2.2.3 - No Timing - Level AAA

    • Success Criterion 2.2.4 - Interruptions - Level AAA

    • Success Criterion 2.2.5 - Re-authenticating - Level AAA

    • Success Criterion 2.2.6 - Timeouts - Level AAA

  • Guideline 2.3 - Seizures and Physical Reactions

    • Success Criterion 2.3.1 - Three Flashes or Below Threshold - Level A

    • Success Criterion 2.3.2 - Three Flashes - Level AAA

    • Success Criterion 2.3.3 - Animation from Interactions - Level AAA

  • Guideline 2.4 - Navigable

    • Success Criterion 2.4.1 - Bypass Blocks - Level A

    • Success Criterion 2.4.2 - Page Titled - Level A

    • Success Criterion 2.4.3 - Focus Order - Level A

    • Success Criterion 2.4.4 - Link Purpose (In Context) - Level A

    • Success Criterion 2.4.5 - Multiple Ways - Level AA

    • Success Criterion 2.4.6 - Headings and Labels - Level AA

    • Success Criterion 2.4.7 - Focus Visible - Level AA

    • Success Criterion 2.4.8 - Location - Level AAA

    • Success Criterion 2.4.9 - Link Purpose (Link Only) - Level AAA

    • Success Criterion 2.4.10 - Section Headings - Level AAA

  • Guideline 2.5 - Input Modalities

    • Success Criterion 2.5.1 - Pointer Gestures

    • Success Criterion 2.5.2 - Pointer Cancellation - Level A

    • Success Criterion 2.5.3 - Label in Name - Level A

    • Success Criterion 2.5.4 - Motion Actuation - Level A

    • Success Criterion 2.5.5 - Target Size - Level AAA

    • Success Criterion 2.5.6 - Concurrent Input Mechanisms - Level AAA

• Principle 3 - Understandable

  • Guideline 3.1 - Readable

    • Success Criterion 3.1.1 - Language of Page - Level A

    • Success Criterion 3.1.2 - Language of Parts - Level AA

    • Success Criterion 3.1.3 - Unusual Words - Level AAA

    • Success Criterion 3.1.4 - Abbreviations - Level AAA

    • Success Criterion 3.1.5 - Reading Level - Level AAA

    • Success Criterion 3.1.6 - Pronunciation - Level AAA

  • Guideline 3.2 - Predictable

    • Success Criterion 3.2.1 - On Focus - Level A

    • Success Criterion 3.2.2 - On Input - Level A

    • Success Criterion 3.2.3 - Consistent Navigation - Level AA

    • Success Criterion 3.2.4 - Consistent Identification - Level AA

    • Success Criterion 3.2.5 - Change on Request - Level AAA

  • Guideline 3.3 - Input Assistance

    • Success Criterion 3.3.1 - Error Identification - Level A

    • Success Criterion 3.3.2 - Labels or Instructions - Level A

    • Success Criterion 3.3.3 - Error Suggestion - Level AA

    • Success Criterion 3.3.4 - Error Prevention (Legal, Financial, Data) - Level AA

    • Success Criterion 3.3.5 - Help - Level AAA

    • Success Criterion 3.3.6 - Error Prevention (All) - Level AAA

• Principle 4 - Robust

  • Guideline 4.1 - Compatible

    • Success Criterion 4.1.1 - Parsing - Level A

    • Success Criterion 4.1.2 - Name, Role, Value - Level A

    • Success Criterion 4.1.3 - Status Messages - Level AA