Non-text elements can cause problems for users of assistive technology, particularly screen reader users. Multimedia content can be inaccessible for hearing and visually impaired users.
[return to top]Each image should have an alt attribute (commonly called an alt tag). The alt attribute should describe the content of the image. A long description should be provided if the image is particularly complex. If an image is used solely for presentation purposes (e.g. spacing or bullets in a list) it should have an empty alt attribute. If an image map is used, each hot spot area should have its own alt attribute.
Writing useful alt attribute text is complex. The following articles may be useful:
Users should be given the option to turn off and control the level of any sound used on your pages.
All animated content and videos should have one or more of the following accessibility features:
You should also provide synchronised captions for audio excerpts where possible. If this is not possible then text transcripts (a list of all the sounds) and text descriptions (an embellished list of all sounds) can also be considered.
Writing useful captions and transcripts can be time consuming. The following articles give tips on how to do it well:
To test that alternative text is well written, disable images in your browser using browser settings or a toolbar and ensure that the full content of the website is available and that alt text is meaningful. Ideally listen to your website with a screen reader [link to screen reader].
To test for audio, video and multimedia alternatives go through each web page and manually verify that the information contained can be accessed in alternatives ways. Check that sound levels can be altered and sound muted.
[return to top]Checkpoint 1.1 Provide text equivalents for every non-text element.
Checkpoint 9.2 Text equivalents for multimedia.
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