DRAFT DOCUMENT

This is a draft document supplied by the WCAG Techniques Task Force. It in no way represents a WCAG Working Group consensus or agreement and is provided for informational and discussion purposes only. The accessibility test listed below should not be construed as required for conformance with the proposed WCAG2.

HTML Test Suite for WCAG 2.0
Test 16 - Alt text for all `img` elements is the empty string ("") if the image is decorative.

W3C Editor's Draft 2005-08-11

Editors:: Chris Ridpath, ATRC, University Of Toronto; Jenae Andershonis, Microsoft Inc.

Abstract

This test case was created by the ATRC at the University Of Toronto. It should not be construed as required for conformance with the proposed WCAG2.

The complete list of tests may be found at http://www.w3.org/WAI/GL/WCAG20/tests/

Comments on this test may be made to the WCAG mailing list.

Status Of This Test

As part of the conformance test process, this test has a status of 'accepted'.

WCAG2 Guideline

Guideline: 1.1 - Provide text alternatives for all non-text content.
Success Criteria: 4. Non-text content that is not functional, is not used to convey information, and does not create a specific sensory experience is implemented such that it can be ignored by assistive technology. How to provide text alternatives that can be ignored by assistive technology . (Informative)

Level 1

The WCAG2 has 3 priority levels for making Web content accessible. This test has a priority of 'Level 1'.

Techniques

The WCAG Working Group has created techniques that describe how Web content may be made accessible. The following techniques are related to this test:

Prerequisite Tests

The following tests must be run before running this test. If any of the prerequisite tests fail then this test is invalid and should not be run.

All img elements have an alt attribute.

Test Process

Procedure

Check each img element and view its Alt text.
Determine if the image is decorative.
Note: For this content, "decorative" is defined as "content that does not provide information, functionality, sensory experience and is neither multimedia nor time-dependent interactive".

Expected Results

Alt text for all img elements is the empty string ("") if the image is decorative.

Fail Instructions

Change the Alt text to an empty string ("") or confirm that the image is not decorative.

Pass Instructions

The following tests are related to this test and may be performed next. There is no requirement that these tests be performed:

Alt text for all img elements is not placeholder text.

Test Files

These test files contain examples of the accessibility problem detectable by this test. They may also contain more accessibility problems than the one described in this test. Please ignore any extraneous accessibility problems in these files.

16-1.html Will fail the test. (Image is decorative and Alt text is not an empty string ("").)

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>OAC Testfile - Check #16 - Positive</title> </head> <body> My poem requires a big space<img src="10pttab.gif" alt="big space" width="5" height="5"/>here. </body> </html>
16-2.html Will pass the test. (Image is decorative and Alt text is an empty string ("").)

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>OAC Testfile - Check #16 - Negative</title> </head> <body> My poem requires a big space<img src="10pttab.gif" alt="" width="5" height="5"/>here. </body> </html>
16-3.html Will fail the test. (Image within link is decorative but Alt text is not an empty string ("").)

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>OAC Testfile - Check #16 - Positive</title> </head> <body> <a><img src="star.gif" alt="red star"/>dogs</a> </body> </html>
16-4.html Will pass the test. (Image within link is decorative and Alt text is an empty string ("").)

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>OAC Testfile - Check #16 - Negative</title> </head> <body> <a><img src="star.gif" alt=""/>dogs</a> </body> </html>