The WCAG 2.0 Success Criteria are more explicit than the existing 508 Standards.  Careful attention has been given to ensure that the Success Criteria are written as objectively testable requirements.  In addition, 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.  We are providing this table comparing the WCAG 2.0 Level A and AA Success Criteria and the corresponding requirements in the existing 508 Standards to clarify the differences.  Where a WCAG 2.0 success criterion is new and does not correspond to a provision in the existing 508 standards, it addresses a deficiency with the existing 508 Standards as identified by the developers of WCAG.  In most cases, agencies with Section 508 compliance testing processes have adapted their procedures to address these accessibility concerns.

There are 38 Level A and AA Success Criteria.  Of these, 22 are phrased differently but equivalent in substance to current 508 requirements.  Content that meets the current 508 requirements would not have to be changed to meet the corresponding success criteria.  Sixteen success criteria are new and content that meets the current 508 requirements might not meet these success criteria.

Proposed (WCAG 2.0 Success Criteria [Level])Existing 508 Corresponding ProvisionSummaryWhat would ChangeComment
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 prerecorded 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 prerecorded video and multimedia. Substantially Equivalent Proposed standard distinguishes between live and prerecorded media.
1.2.3 Audio Description or Media Alternative (Prerecorded) [A] 1194.22(b) and .24(d) Provides for audio description of prerecorded 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 existing standard is specific to HTML image maps and data tables.
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  
1.4.1 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.
1.4.2 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  
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.
2.1.2 No Keyboard Trap [A] None Provides that the keyboard focus is not trapped when the keyboard is used for navigation New  
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.
2.4.3 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  
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”.
3.1.1 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  
3.2.1 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
3.2.3 Consistent Navigation [AA] None Provides that repeated navigational components occur in the same relative order each time they are encountered New  
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.”
3.3.2 Labels or Instructions [A] 1194.21(l) and .22(n) Provides for labels or instructions when content requires user input
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  
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”.