Alt attribute

As alt text refers to the HTML code that part of the image tags and similar elements that will contain a clue as to what is expressed in the illustrated element. In addition to images, the alt attribute is also used for example for Java applets and input fields.

Example:

< img = " koelner - dom.jpg " height = " 250 " width = "300 " alt = " The Cologne Cathedral in the evening light. " / >

This line of code is usually Is the picture koelner - dom.jpg the current image can not be loaded, or the format is not supported by the web browser instead, the text " The Cologne Cathedral in the evening light. " Is displayed. This is to visually impaired people or site visitors whose browsers can not display images or should convey the content of an image. It is according to the official HTML specification as a defect to dispense with images on these alt text.

Meanwhile, this alt text is also regarded as a criterion in the on-page search engine optimization, because the search engines detect above this text also the content of images.