Is an 'alt' attribute required in img tags?

[robsch]

My images don't get fetched and shown if I don't supply a non empty alt attribute. src is empty. Does it have anything to do with #155 - does the alt tag cause a min-height?

[robsch]

Seems so. If there is no initial height blazy does not work. Some text in the alt tag causes a certain heigt. But you can also create height with css: display: block; height: 100px;