Accessibility News

Web Accessibility Comparisons: WCAG 2.0 vs. Section 508

Written by Alex Margau | Oct 19, 2023 2:00:00 PM

Web content accessibility has become an increasingly recognized necessity, with US laws such as the ADA Title III  website accessibility law or Section 508 of the Rehabilitation Act, consumed by both users with disabilities and website owners, as their websites are designed to meet the needs of users with disabilities and also help website owners determine the requirements for compliance and avoid potential web content accessibility lawsuits. 

In previous blog posts we looked at some of these web accessibility compliance requirements, which we summed up in the form of checklists for both the most recent version of the WCAG, web content accessibility guidelines version 2.2, and the Original 508 Standard, which is still the most commonly known version. Below we take a step backwards and compare the Original 508 Standard to the 2.0 version of the WCAG Success Criteria, in order to understand the development of the Revised 508 Standard, as well as of the WCAG, as it has been proven that, with each update, web accessibility compliance is better defined and its requirements better understood. According to the United States’ Access Board “the WCAG 2.0 Success Criteria are more explicit than the existing 508 Standards” and “unlike the existing 508 Standards, WCAG 2.0 is written in a way that is technology neutral and is therefore directly applicable to a wide range of content types and formats.”

The web content accessibility guidelines of the WCAG 2.0 has 38 Level A and AA Success Criteria of which only 22 have some form of equivalent in the 508 Standard. The below table, based on the comparison done by the Access Board, outlines the differences as well as what parts of the 508 Standard might not meet some of the success criteria in the WCAG. For ease of reading, we have grouped the data into 2 tables, one for the equivalent provisions for content accessibility, and one for the new ones. 

 

Equivalent Provisions for Content Accessibility

 

Proposed (WCAG 2.0 Success Criteria [Level])

Existing 508 Corresponding Provision

Summary

What would Change

Comment

1.1.1 Non-text Content [A]

1194.22(a)

Provides for text alternatives of images and other non-text content, including user interface components

Substantially Equivalent

Proposed standard provides additional detail for 8 common categories of non-text content

1.2.1 Prerecorded Audio-only and Video-only [A]

1194.22(a)

Provides that pre-recorded audio is available in a visible format and that silent animations are available in an audible format

1.2.2 Captions (Prerecorded) [A]

1194.22(b) and .24(c)

Provides for synchronized captioning of pre-recorded video and multimedia

Substantially Equivalent

Proposed standard distinguishes between live and pre-recorded media

1.2.3 Audio Description or Media Alternative (Prerecorded) [A]

1194.22(b) and .24(d)

Provides for audio description of pre-recorded video and multimedia

1.2.4 Captions (Live) [AA]

1194.22(b) and .24(c)

Provides for captioning of live video and multimedia

1.2.5 Audio Description (Prerecorded) [AA]

1194.22(b) and .24(d)

Provides for audio description of live video and multimedia

1.3.1 Information and Relationships [A]

1194.22(e) through (h)

Provides that information, structure, and relationships conveyed visually are available to users of assistive technology

Provides that semantic markup be used for headings, lists, emphasized or special text, and tabular data, including the association of data cells with their headers

Substantially Equivalent

Proposed standard is written broadly and is technology neutral, whereas the existing standard is specific to HTML image maps and data tables

1.4.1 Use of Color [A]

1194.21(i) and .22(c)

Provides that information and prompts are not conveyed only through color

Substantially Equivalent

No technical difference

1.4.5 Images of Text [AA]

1194.21(f)

Provides for the use of text, as opposed to images of text

Substantially Equivalent

Proposed standard provides detail for two situations where images of text are permissible

2.1.1 Keyboard [A]

1194.21(a)

Provides for functionality when using only the keyboard interface

Substantially Equivalent

Proposed standard clarifies the requirement by emphasizing the method of input, rather than the nature of the output

2.2.1 Timing Adjustable [A]

1194.22(p)

Provides for flexible time limits

Substantially Equivalent

Proposed standard provides additional options to the single approach specified in the existing provision (that the user "be alerted and given sufficient time to indicate more time is required")

2.2.2 Pause, Stop, Hide [A]

1194.21(h)

Provides for user control over moving, blinking, scrolling, and information that updates automatically

Substantially Equivalent

Proposed standard specifies options (pause, stop, hide, or control the frequency) instead of "displayable in at least one non-animated presentation mode", and allows for when animation "is part of an activity where it is essential" (for example, data that is being updated in real time)

2.3.1 Three Flashes or Below Threshold [A]

1194.21(k) and .22(j)

Provides that nothing flashes more than three times per second, unless the flash is very small and does not contain too much red

Substantially Equivalent

Proposed standard takes into consideration the size and hue of the flash

2.4.1 Bypass Blocks [A]

1194.22(o)

Provides for a skip navigation link or other means to bypass repetitive content

Substantially Equivalent

Proposed standard uses the phrase "blocks of content that are repeated" instead of just "repetitive navigation links"

2.4.2 Page Title [A]

1194.22(i)

Provides for descriptive and informative page titles

Substantially Equivalent

Proposed standard is for all types of content instead of just HTML frames

2.4.7 Focus Visible [AA]

1194.21(c)

Provides that the keyboard focus is visually apparent when using the keyboard to navigate

Substantially Equivalent

Proposed standard uses the phrase "indicator is visible" instead of "well-defined on-screen indication"

3.2.1 On Focus [A]

1194.21(l) and .22(n)

Provides that user interface components do not initiate a change of context when receiving focus

Substantially Equivalent

Proposed standard is explicit instead of having the requirement implicit in that "the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues"

3.2.2 On Input [A]

1194.21(l) and .22(n)

Provides that changing the setting of user interface components does not automatically cause a change of context

3.2.4 Consistent Identification [AA]

1194.21(e)

Provides that components having the same functionality are identified consistently

Substantially Equivalent

Proposed standard is for all types of content instead of just "bitmap images"

3.3.1 Error Identification [A]

1194.21(l) and .22(n)

Provides that automatically detected input errors are identified and described in text to the user

Substantially Equivalent

Proposed standard is explicit instead of having the requirement implicit in that "the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues"

4.1.2 Name, Role, Value [A]

1194.21(d)

Provides that sufficient information (including identity, operation, and state) about user interface components is available to assistive technology

Substantially Equivalent

Proposed standard uses the phrase "programmatically determined" instead of "available to assistive technology"



Content Accessibility Provisions Without Equivalent

 

Proposed (WCAG 2.0 Success Criteria [Level])

Existing 508 Corresponding Provision

Summary

What would Change

Comment

1.3.2 Meaningful Sequence [A]

None

Provides for a reasonable and logical reading order  when using assistive technology

New

 

1.3.3 Sensory Characteristics [A]

None

Provides that instructions are not conveyed only through sound, shape, size, or visual orientation

New

 

1.4.2 Audio Control [A]

None

Provides that there is a way to stop, pause, mute, or adjust volume with audio that plays automatically

New

 

1.4.3 Contrast (Minimum) [AA]

None

Provides for specified contrast between foreground and background of text and images of text

New

 

1.4.4 Resize Text [AA]

None

Provides tor content that remains readable and functional when the font size is doubled

New

 

2.1.2 No Keyboard Trap [A]

None

Provides that the keyboard focus is not trapped when the keyboard is used for navigation

New

 

2.4.3 Focus Order [A]

None

Provides for a keyboard-oriented navigation order that is reasonable and logical. Provides that links, form elements, and other user interface controls and components have a reasonable and logical navigation order

New

 

2.4.4 Link Purpose (In Context) [A]

None

Provides that the purpose of any link is understandable from its text or context

New

 

2.4.5 Multiple Ways  [AA]

None

Provides for two or more means to locate content

New

 

2.4.6 Headings and Labels [AA]

None

Provides that headings and labels are descriptive

New

 

3.1.1 Language of Page [A]

None

Provides that the default language of content is exposed  to assistive technology

New

 

3.1.2 Language of Parts [AA]

None

Provides that changes in language are exposed to assistive technology

New

 

3.2.3 Consistent Navigation [AA]

None

Provides that repeated navigational components occur in the same relative order each time they are encountered

New

 

3.3.3 Error Suggestion [AA]

None

Provides that the system makes suggestions for correction when input errors are automatically detected and suggestions are available

New

 

3.3.4 Error Prevention (Legal, Financial, Data) [AA]

None

Provides that when legal, financial, or test data can be changed or deleted the changes or deletions can be reversed, verified, or confirmed

New

 

4.1.1 Parsing [A]*

None

Provides that significant HTML/XHTML validation and parsing errors in source code are avoided

New

 

* As of the latest version of the WCAG, the 2.2 version, this Success Criteria has been eliminated. 

The Original 508 Standard was thought in line with the web content accessibility guidelines of the   WCAG 1.0, whereas the Revised 508 Standard  relies on the web content accessibility guidelines of the WCAG 2.0. However, at this time, the most current version of the WCAG is version 2.2, which removes one of the success criteria in previous versions, and adds nine new ones instead.