Stop feeling guilty about alt=""

My favorite resource for deciding when to add an alt tag is the Alt Decision Tree from the W3C. In addition to being a useful guide, it highlights something that isn't well known – null alt tags are not only perfectly acceptable, but even encouraged.

Decorative images, as the name implies, don't add context to the page. Maybe the information in the image is already covered in nearby text, or maybe its sole purpose is to look nice. Either way, screen readers need to ignore these images. Omitting the alt attribute entirely isn't an option because some screen readers will announce the file name, adding audible clutter. A slight improvement is using aria-hidden, but due to limited support, the W3C recommends null alt attributes over aria-hidden.