Alt text
Alt text is a short written description attached to an image on a web page, read aloud by screen readers and used by search engines.
- Alternative text
- Alt attribute
- Text alternative
What it means
Every image on a web page can carry a line of text saying what it shows, held in the image’s alt attribute. A screen reader reads it aloud, and Shopify notes that if an image cannot load, “the alt text displays instead”.1 The W3C, which publishes the web’s accessibility standards, puts it plainly: “Images must have text alternatives that describe the information or function represented by them.”2
Search engines read it too. Google says it uses alt text “along with computer vision algorithms and the contents of the page to understand the subject matter of the image”. It also warns that stuffing alt text with keywords “may cause your site to be seen as spam”.3
Imports handle it differently. Shopify’s product CSV has an Image alt text column, and suggests “125 characters or fewer”.1 WooCommerce’s core importer “cannot add, edit, or update alt text for product images”, so there it has to be added after the import.4
Think of it like this
Describing a photo to a friend over the phone takes the same skill. You say what matters in it, in a sentence, without listing every detail or repeating the same word five times.
For example
Missing: no alt text at all. Stuffed: “kettle cheap kettle best kettle buy kettle”. Useful: “Brackmore 1.7 litre kettle in matt black on its power base”, which says what the picture shows in words a shopper would use.
Why it matters
Without alt text, a shopper using a screen reader cannot tell what a product picture shows, and search engines have less to go on. Written from the product’s own values (brand, type, colour), it stays accurate across thousands of images.
Not to be confused with
Alt text is not the image’s file name. Google says a file name gives only “very light clues” about an image, while alt text is the “most important attribute” for describing one.3
Sources
- Shopify Help Center. Using CSV files to import and export products.
- W3C Web Accessibility Initiative (WAI). Images Tutorial.
- Google Search Central. Image SEO Best Practices.
- WooCommerce documentation. Product CSV Importer and Exporter.