Images - alt text vs long description

There are 2 types of text alternatives:

• a short one (alt attribute), and

• a long one (can be implemented in several ways, but it’s the content of the text alternative that matters).

For simple images, you might only need an alt attribute (150 characters max, ~100 more ideally). It should serve as a decent text equivalent or replacement for the image.

No need to use the word “image” in the alt-text as this is clear by virtue of the <img> element used.

For more complex images (charts, graphs, infographics, etc.), a long text description is needed. You want to be able to replace the image with that text description and still be able to get the same amount of information from it as you would just from the image.