An image with no alt text

The image below has no alt text, so a screen reader skips over it as if it were not there.

Why alt text matters

An image with no alt attribute is a blank spot for anyone using a screen reader and a mystery to a crawler trying to read the page. Alt text is the caption the software reads. An image that carries meaning needs a short, specific description of what it shows. An image that is only decoration should carry an empty alt so the software knows to skip it on purpose.

Getting it right

Describe what the image shows and does, not that it is an image. Keep it short and do not stuff it with keywords. Never leave the attribute off entirely. A missing alt and an empty alt look almost the same in the markup but mean the opposite thing to the software that reads them.