What is Alt Text?

Alt text (short for "alternative text") is a short text description you attach to an image on your website. It is not visible on the page itself — it lives in the code behind the image and describes what the image shows.

Imagine describing a picture over the phone to a friend who cannot see it: "it is a red sports car parked in front of a red house". That is exactly what alt text does. Both programs that read pages aloud for people with low vision and Google's crawlers are effectively blind — they cannot "see" an image, only read the text that describes it. Alt text is the image's voice.

It serves two jobs at once: it makes the site usable for people who use screen readers, and it helps Google understand and rank your images in image search.

Why is alt text important for your business?

Alt text is both an accessibility and an SEO issue. People with visual impairments can access your content, which is thoughtful and in some cases a legal requirement. At the same time, the text helps your images show up in Google image search, which can bring in extra visitors.

Alt text also appears if the image fails to load for any reason — then the visitor sees the description instead of a broken box. A small thing that makes the site feel more professional.

Alt text in practice

Say a furniture shop has a product photo of a sofa. Bad alt text is "image123". Good alt text is "grey fabric sofa with three wooden legs, seen from a front angle". The latter helps both a customer with low vision and Google — and can mean the sofa appears when someone searches for "grey fabric sofa" in image search.

A good rule of thumb is to write as if you are describing the image aloud to someone who cannot see it: short, concrete, and honest. Avoid stuffing in keywords — just describe what is actually there.