meta element has no refresh delay

  • Rule Type:atomic
  • Rule Id: bc659a
  • Last modified: Aug 19, 2020
  • Accessibility Requirements Mapping:
    • 2.2.1 Timing Adjustable (Level A)
      • Learn More about 2.2.1 Timing Adjustable
      • Required for conformance to WCAG 2.0 and later on level A and higher.
      • Outcome mapping:
        • Any failed outcomes: success criterion is not satisfied.
        • All passed outcomes: success criterion needs further testing.
        • An inapplicable outcome: success criterion needs further testing.
    • 2.2.4 Interruptions (Level AAA)
      • Learn More about 2.2.4 Interruptions
      • Required for conformance to WCAG 2.0 and later on level AAA.
      • Outcome mapping:
        • Any failed outcomes: success criterion is not satisfied.
        • All passed outcomes: success criterion needs further testing.
        • An inapplicable outcome: success criterion needs further testing.
    • 3.2.5 Change on Request (Level AAA)
      • Learn More about 3.2.5 Change on Request
      • Required for conformance to WCAG 2.0 and later on level AAA.
      • Outcome mapping:
        • Any failed outcomes: success criterion is not satisfied.
        • All passed outcomes: success criterion needs further testing.
        • An inapplicable outcome: success criterion needs further testing.
    • H76: Using meta refresh to create an instant client-side redirect
      • Learn More about technique H76
      • Not required to conformance to any W3C accessibility recommendation.
      • Outcome mapping:
        • Any failed outcomes: technique is not satisfied.
        • All passed outcomes: technique needs further testing.
        • An inapplicable outcome: technique needs further testing.
  • Input Aspects:

Description

This rule checks that the meta element is not used for delayed redirecting or refreshing.

Applicability

The rule applies to the first valid <meta http-equiv="refresh"> element with a content attribute in a document.

Expectation

The time of the content attribute is 0 or greater than 72000 (20 hours).

Note: See Refresh state (http-equiv="refresh") for a precise description on how to determine the time.

Assumptions

  • This test assumes no functionality was provided by the website for the user to adjust the timer.
  • This test assumes that the refresh was not essential, which is listed as a valid exception to SC 2.2.1.

Accessibility Support

Not all major web browsers parse the value of the content attribute in the same way. This can cause redirects to happen in some browsers, but not in others. This can cause some pages to pass this rule, while still having a redirect in a minority of web browsers.

Background

This rule is designed specifically for 2.2.1 Timing Adjustable, which can be satisfied if the time limit is over 20 hours long. All pages that fail this because of a "refresh" meta element also do not satisfy 2.2.3 No Timing and 3.2.5 Change on Request. In order to adequately test the expectation, some of the passed examples do not satisfy 2.2.3 No Timing and 3.2.5 Change on Request.

Test Cases

Passed

Passed Example 1

Open in a new tab

Redirects immediately.

<head>
	<meta http-equiv="refresh" content="0; URL='https://github.com'" />
</head>

Passed Example 2

Open in a new tab

First valid <meta http-equiv="refresh"> redirects immediately.

<head>
	<meta http-equiv="refresh" content="0; http://example.com" />
	<meta http-equiv="refresh" content="5; http://example.com" />
</head>

Passed Example 3

Open in a new tab

Redirects after more than 20 hours.

<head>
	<meta http-equiv="refresh" content="72001; http://example.com" />
</head>

Failed

Failed Example 1

Open in a new tab

Refreshes after 30 seconds.

<head>
	<meta http-equiv="refresh" content="30" />
</head>

Failed Example 2

Open in a new tab

Redirects after 30 seconds.

<head>
	<meta http-equiv="refresh" content="30; URL='https://github.com'" />
</head>

Failed Example 3

Open in a new tab

First <meta http-equiv="refresh"> element is not valid, second one redirects after 5 seconds.

<head>
	<meta http-equiv="refresh" content="0: http://example.com" />
	<meta http-equiv="refresh" content="5; http://example.com" />
</head>

Failed Example 4

Open in a new tab

Redirects after exactly 20 hours.

<head>
	<meta http-equiv="refresh" content="72000; http://example.com" />
</head>

Inapplicable

Inapplicable Example 1

Open in a new tab

No content attribute.

<head>
	<meta http-equiv="refresh" />
</head>

Inapplicable Example 2

Open in a new tab

No http-equiv="refresh" attribute.

<head>
	<meta content="30" />
</head>

Inapplicable Example 3

Open in a new tab

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="0: http://example.com" />
</head>

Inapplicable Example 4

Open in a new tab

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="-00.12 foo" />
</head>

Inapplicable Example 5

Open in a new tab

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="; 30" />
</head>

Inapplicable Example 6

Open in a new tab

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="" />
</head>

Inapplicable Example 7

Open in a new tab

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="+5; http://example.com" />
</head>

Inapplicable Example 8

Open in a new tab

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="foo; URL='https://github.com'" />
</head>

Glossary

Outcome

An outcome is a conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

  • 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 passed or 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 passed, failed and 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 incomplete outcome.


Useful Links


Implementations

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.

ToolConsistencyCompleteReport
SortSiteconsistentYesView Report
AlfaconsistentNoView Report
QualWebconsistentNoView Report

Acknowledgments

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