Alt text for marketplace listing images

What Google says

Google calls alt text the most important attribute for giving it information about an image, and says it uses alt text together with computer vision and the content of the page to understand what an image shows.^[1] It warns against filling alt attributes with keywords, which it treats as keyword stuffing, and suggests short, descriptive file names, such as my-new-black-kitten.jpg rather than IMG00023.JPG.^[1]

What the W3C says

WCAG success criterion 1.1.1 asks for a text alternative for non-text content.^[2] For an informative image, the W3C's tutorial says the text alternative should convey the meaning or content the image shows, usually in a short phrase or sentence.^[3] A purely decorative image gets an empty alt attribute, so screen readers skip it.^[4]

A pattern for listing photos

Name the item, then what this photo shows that the others do not. For example: "Walnut dining table, extended to seat eight", "Walnut dining table, close-up of the grain", "Studio apartment, kitchen with a gas stove". Keep it to one sentence, and leave out "image of": a screen reader already says it is an image.

Common mistakes on listing pages

• The same alt text on each photo of a listing, often the listing title with a number added. It tells a shopper using a screen reader nothing about how the photos differ.
• Empty alt text on photos of the item, which hides them from screen readers.
• A list of keywords instead of a description.

Where Topit fits today

Topit does not write alt text. Its free listing photo audit scores the photos themselves for lighting, sharpness, framing, clutter and clarity, and shows which listings lead with a weaker photo than one they already have. The two work together: alt text tells screen readers and search engines what a photo shows, and the lead photo is what shoppers see first.