Textual description of an image, read by screen readers and crawlers.
Alt text is a required accessibility attribute and a significant SEO signal — it is how screen readers describe product images to visually impaired shoppers and how Google understands the subject of an image for Google Images and Google Shopping. Good alt text describes the product concretely (`black cotton crew-neck t-shirt, front view`), not decoratively (`image1.jpg`) and not keyword-stuffed (`buy cheap best t-shirt online`). Shopify does not populate alt text automatically; on most catalogs it is the highest-ROI SEO field still empty.
