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This is an early unpublished editor's draft; content is incomplete and subject to change.

Text contrast sufficient (minimum)

Core requirement

The default visual presentation of text meets @@[contrast measure to be determined].

Applies when text is presented, including text embedded in an image format.

Except when the text is:

  • also present elsewhere in the page/view which meets the requirement
  • part of an inactive interactive element
  • pure decoration
  • not visible to anyone
  • part of a picture that includes significant other visual content
  • part of a logo or brand name

Transparency can cause testing issues, but should be tested as the rendered color.

The contrast algorithm used in WCAG 3 is yet to be determined. For this draft, the requirement assumes the algorithm will include a size/weight factor. If the algorithm does not include size/weight, it will need to be added to this requirement text.

A separate requirement may be needed if red/green color vision deficiency (CVD) is not accounted for within the contrast algorithm.

Tests

Procedure

For each foreground and background combination of text:

  1. Identify the foreground color.
  2. Identify the background color.
  3. Check the contrast of text meets the [TBD algorithm].

Expected results

Key Terms

accessibility support set

group of user agents and assistive technologies you test with

The AGWG is considering defining a default set of user agents and assistive technologies that they use when validating guidelines.

Accessibility support sets may vary based on language, region, or situation.

If you are not using the default accessibility set, the conformance report should indicate what set is being used.

accessibility supported

available and working in the user agents and assistive technology in the accessibility support set

The working group intended to include a default accessibility support set. See Default accessibility support set #277.

actively available

available for the user to perceive and use

On the web, “actively available” is content that is not inert (see explanation of inert in HTML).

component

grouping of elements for a distinct function

conformance scope

A product, set of Pages/Views, content, functionality, or components selected to be part of a conformance claim. Where a View or Page is part of a Process, all the Views or Pages in the process must be included.

How a person or organization selects the set is not defined in WCAG3. There maybe informative guidance on selecting a suitable set in future (similar to WCAG-EM), but regional laws or regulations may provide a methodology.

content

information, sensory experience and interactions conveyed

default visual presentation

formatting of content defined by the author without any modifications or customizations by the end user

interactive element

element that responds to user input and has a distinct programmatically determinable name

In contrast to non-interactive elements. For example, headings or paragraphs.

non-interactive element

element that does not respond to user input and does not include sub-parts

If a paragraph included a link, the text either side of the link would be considered a static element, but not the paragraph as a whole.

Letters within text do not constitute a “smaller part”.

page

non-embedded resource obtained from a single URI using HTTP plus any other resources that are used in the rendering or intended to be rendered together

Where a URI is available and represents a unique set of content, that would be the preferred conformance unit.

platform

software, or collection of layers of software, that lies below the subject software and provides services to the subject software and that allows the subject software to be isolated from the hardware, drivers, and other software below

Platform software both makes it easier for subject software to run on different hardware, and provides the subject software with many services (for example, functions, utilities, libraries) that make the subject software easier to write, keep updated, and work more uniformly with other subject software.

A particular software component might play the role of a platform in some situations and a client in others. For example a browser is a platform for the content of the page but it also relies on the operating system below it.

The platform is the context in which the conformance scope exists.

process

series of views or pages associated with user actions, where actions required to complete an activity are performed, often in a certain order, regardless of the technologies used or whether it spans different sites or domains

programmatically determinable

meaning of the content and all its important attributes can be determined by software functionality that is accessibility supported

view

content that is actively available in a viewport including that which can be scrolled, zoomed, or panned to, and any additional content that is conditionally shown while leaving the rest of the content in the viewport actively available

viewport

object in which the platform presents content

The author has no control of the viewport and almost always has no idea what is presented in a viewport (for example, what is on screen) because it is provided by the platform. On browsers the hardware platform is isolated from the content.

Content can be presented through one or more viewports. Viewports include windows, frames, loudspeakers, and virtual magnifying glasses. A viewport may contain another viewport. For example, nested frames. Interface components created by the user agent such as prompts, menus, and alerts are not viewports.