This rule checks if it is possible to use standard keyboard navigation to navigate through all content on a web page without becoming trapped in any element.
Note: This rule only applies to HTML and SVG. Thus, it is a partial check for WCAG 2.0 success criterion 2.1.2, which applies to all content.
For each target element focus can cycle to the browser UI by using standard keyboard navigation.
Note: Cycling back to the browser UI can be done both by moving forward through the tab order and by moving backwards. It is not possible to fulfill this expectation by using browser specific shortcuts to return to the browser UI.
- The focus order in keyboard navigation is cyclical, not linear, meaning that the focus order will cycle to the first/last element when it moves away from the last/first element.
- The Browser UI is part of the focus navigation cycle of the page.
There are no major accessibility support issues known for this rule.
- Understanding Success Criterion 2.1.2: No Keyboard Trap
- G21: Ensuring that users are not trapped in content
- F10: Failure of Success Criterion 2.1.2 and Conformance Requirement 5 due to combining multiple content formats in a way that traps users inside one format type
No trap for keyboard navigation.
<a href="#">Link 1</a> <button>Button1</button>
Keyboard trap one element.
<a href="#">Link 1</a> <button onblur="setTimeout(() => this.focus(), 10)"> Button1 </button>
Keyboard trap group.
<button onblur="setTimeout(() => this.nextElementSibling.focus(), 10)"> Button1 </button> <button onblur="setTimeout(() => this.previousElementSibling.focus(), 10)"> Button2 </button> <button> Button3 </button>
A focusable element between keyboard traps.
<button onblur="setTimeout(() => this.focus(), 10)">Button 1</button> <button>Button 2</button> <button onblur="setTimeout(() => this.focus(), 10)">Button 3</button>
No focusable element.
<button type="button" disabled>Click Me!</button>
Hidden element using
<button type="button" style="display:none;">Click Me!</button>
Hidden element using
<a href="#" style="visibility:hidden;">Link 1</a> <button style="visibility:hidden;">Button1</button>
Namespaced elements are not limited to elements described in a specification. They also include custom elements. Elements such as
title have a different namespace depending on where they are used. For example a
title in an HTML page usually has the HTML namespace. When used in an
svg element, a
title element has the SVG namespace instead.
- Inapplicable: No part of the test subject matches the applicability
- Passed: A test target meets all expectations
- Failed: A test target does not meet all expectations
Note: A rule has one
failed outcome for every test target. When there are no test targets the rule has one
inapplicable outcome. This means that each test subject will have one or more outcomes.
Note: Implementations using the EARL10-Schema can express the outcome with the outcome property. In addition to
inapplicable, EARL 1.0 also defined an
incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such "interim" results can be expressed with the
Standard keyboard navigation
Standard keyboard navigation entails using one or more of the following:
- Tab key
- Arrow keys
- Esc key
- Enter key
- Space key
Expected behavior of standard keyboard navigation keys:
- Tab key: Skipping forward between focusable elements
- Shift+Tab: Skipping backwards between focusable elements
- Arrow keys: Navigate input elements, e.g. up/down drop down, between radio buttons etc.
- Esc key: Close or cancel, e.g close a modal
- Enter key: Select or activate the element in focus (same as clicking with mouse)
- Space key: Select input elements, e.g. drop downs, radio buttons etc.
- Github issues related to this rule
- Propose a change to the rule
- Test case file for use in the WCAG-EM Report Tool
This section is not part of the official rule. It is populated dynamically and not accounted for in the change history or the last modified date. This section will not be included in the rule when it is published on the W3C website.
Implementation reports are not provided for this rule.