Each information-carrying image is provided with an appropriate textual alternative.

Informative images can be illustrations (painting, drawing, photo, comic strip, map, timeline, label, etc.), graphs, data tables. In the case of illustrations, it is important to specify in the alternative text the nature of the document and the description.

Objectives

• Allow readers placed in contexts where images are not perceptible (synthetic voice, screen reader, immersive reading) to understand the meaning of images that they cannot see.

Implementation

• Give each img element concerned an alt attribute reproducing the information, a link adjacent to the image playing the same role, either in the content of the page, in the immediate context of the image. In the latter case, the alternative can indicate the presence of this description and refer to it.

Control

• Check that the alt attribute of each img element concerned reproduces the information carried by the image.
• Check the presence and relevance of the extended description if applicable.
• Check understanding in the absence of the image.

Validation

• Reported by ACE.
• Needs to be human verified.