Missing alt text is the single most common accessibility issue we see on online stores — and it's also one of the easiest to fix, because it needs no code, no developer, and no budget. Just a few honest sentences. This guide covers what alt text is for, what to write, what to skip, and how to find the images on your store that are missing it.
Alt text (short for "alternative text") is a written description attached to an image. Most visitors never see it. But for a customer using a screen reader — software that reads the page aloud, used by people who are blind or partially sighted — the alt text is the image. If your product photo has no alt text, the screen reader announces something like "image" or reads out the filename: "IMG underscore four-oh-two-seven dot jpeg." That customer now has no idea what you're selling.
Alt text also appears if an image fails to load, and search engines read it to understand what's in your photos. So the same few words serve customers who can't see the image, customers on bad connections, and your Google ranking. Few fixes pay off three ways at once.
Describe what a sighted customer learns from looking at the image — nothing more, nothing less. Before you write anything, ask: if a friend were on the phone and couldn't see this photo, what would I tell them? You wouldn't say "product image." You'd say "it's a navy wool jumper with a round neck and ribbed cuffs." That's your alt text.
Here's the difference in practice:
Notice what the good versions have in common: they mention the details a customer actually shops on — colour, material, shape, how it's worn or used. If your product photos exist to show something, the alt text should say that something.
Multiple photos of one product. Don't repeat the same description five times. Give each image its own job: "Front view of the satchel," "Interior showing the laptop sleeve," "Satchel worn crossbody by a model." A screen reader user gets the same tour of the product a sighted shopper does.
Images containing text. If a banner image says "Summer sale — 20% off everything," the alt text must include those words, because a screen reader can't read text that's baked into an image. Better still, put important text in real HTML rather than inside images at all.
Variant swatches. Those little colour circles on product pages are images too. "Swatch 3" tells a customer nothing; "Forest green" tells them what they need.
You don't need a developer. On Shopify, open a product, click an image, and choose "Edit alt text." WooCommerce has an "Alternative text" field in the media library for every image. Wix, Squarespace, and BigCommerce all have similar fields in their image settings. The work isn't technical — it's just sitting down and writing honest descriptions, a product at a time. Start with your bestsellers and your homepage, since those get the most visitors.
An automated scanner — including ours — can tell you which images are missing alt text. It can't tell you whether the alt text you've written is any good. "Product image" passes an automated check and still fails every real customer who relies on it. That's one reason automated testing only catches around 57% of accessibility issues: the rest need human judgement. So use a scan to find the gaps, then use your own knowledge of your products — nobody knows them better — to fill those gaps well.
Claresto scans your store against WCAG 2.2 AA and lists every image without alt text, in plain English, with fix guidance. Scan your store free →
Alt text is one of the rare accessibility fixes that's entirely in your hands, costs nothing, and helps customers and search rankings on the same afternoon. Describe your products the way you'd describe them to a friend on the phone, and you're most of the way there.