# What is Alt text?

> Alt text is a short written description of an image, added in a website's code, that screen readers read aloud and search engines use to understand the picture.

- Source: https://nerdsharks.com/glossary/alt-text
- Publisher: Nerdsharks (Exeter, Devon, UK)
- Updated: 2026-09-26

Also called: alt tag, alt attribute, alternative text, image description.

Every image on a web page can carry a hidden description called alt text, short for alternative text. Blind and partially sighted people using screen readers hear it read aloud, and it appears if the image fails to load.

Google also reads alt text to understand what an image shows, which helps with image search. The aim is to describe the image usefully, not to cram in keywords.

Purely decorative images, like a background pattern, should have empty alt text so screen readers skip them.

## Why it matters for a small business

It is a legal and practical part of making your site usable by disabled customers, and it helps your work photos appear in Google Images. Writing it takes seconds per picture; leaving it out is one of the most common accessibility failures.

**Example:** Instead of ‘IMG_4412.jpg’ or ‘plumber plumber Exeter plumber’, a photo gets the alt text ‘New combi boiler fitted in a kitchen cupboard in Exeter’.