Alt Text on Product Images: What a Screen Reader User Actually Needs
Most product alt text is either empty or a copy of the product title. Neither tells a blind shopper what the product looks like, and that is the whole point.
A blind shopper opens a product page. The screen reader reaches the main image and announces the file name, or the product title repeated word for word, or nothing at all. She has no idea what colour the jacket is, whether it has a hood, or what the fit looks like, and the page has given her no way to find out. The image is the product, and the alt text is the only version of it she gets.
Good alt text is not a description of the file. It is the information the image carries that the surrounding text does not. On a product page, that is usually the visual facts a sighted shopper takes in at a glance.
What to write, and what to leave out
Write what the image shows that the text does not say. Colour, pattern, cut, material, and visible details: a navy wool coat with a notched lapel and tortoiseshell buttons, not a coat. If the product title already says navy wool coat, do not repeat it. The alt text should add the details, not echo the title.
Leave out the words image of and picture of. Screen readers announce the element as an image already, so the phrase is redundant. Leave out the marketing language too. A shopper does not need to hear that the coat is effortlessly chic. She needs to know it has a hood.
The images that need no alt text at all
Decorative images get an empty alt attribute, alt with no value, so the screen reader skips them. Swatch thumbnails that sit next to a colour name do not need alt text that repeats the colour, because the name is already there as text. Icons inside a button with visible text are decorative and should be hidden from assistive technology with aria-hidden.
The mistake is treating every image the same. An empty alt on the main product image hides the product. A long description on a decorative divider wastes the shopper's time. The test is simple: if removing the image would remove information, it needs alt text. If it would not, it does not.
Alt text at scale, without a rewrite project
Most stores have thousands of product images, and rewriting all of them by hand is not a realistic first step. Start with the top sellers and the products with the most image views, and write alt text for the main image on each. Then work through the rest in traffic order, a batch a week.
Build it into the product upload flow so the problem stops growing. A required alt text field on image upload, with a one-line guide and an example, costs a minute per product and ends the backlog. The guide should say what the alt text is for, in one sentence, because the person uploading the photo is the one who can see it.
Related reading: Accessible Store Locators and Pickup Selection: Maps Are Not the Only Way In, Testing Accessible Names on Header Icons: Search, Account, and Cart, ADA Risk in Age Gates and Date of Birth Fields.
Frequently asked questions
What should product image alt text say?
The visual facts the surrounding text does not already state: colour, pattern, cut, material, and visible details. If the product title already says navy wool coat, the alt text should add the lapel, the buttons, and the fit, not repeat the title.
Should alt text start with image of?
No. Screen readers already announce the element as an image, so the phrase is redundant. Start with the description itself.
Which images need empty alt text?
Decorative images, icons inside buttons that already have visible text, and thumbnails next to a colour name that already states the colour. An empty alt attribute tells the screen reader to skip the image entirely.
How do I fix alt text on thousands of product images?
Start with the top sellers and the most viewed products, writing alt text for the main image on each. Then work through the rest in traffic order, and add a required alt text field to the upload flow so the backlog stops growing.