What is the benefit to add empty alt=""? and which alt should be used this alt="" or alt=" "?

accessibility, screen-readers, xhtml

Solution

Other answers have pointed out the requirements in the standard. Here is a practical example:

Given blank alt text, lynx will render:

Given a missing alt attribute, lynx will render:

filename.jpg

You don't want your content to have irrelevant filenames scattered throughout.

Problem

What is the benefit to add null alt=""? is it only to pass validation or it has more reason and how it should be write? like this, no space ``` alt="" ``` or this with one blank space ``` alt=" " ```

Original source