Alt Attributes

Alt attributes (alt text) are short descriptions added to an image's HTML tag. Screen readers read them aloud for visually impaired users, browsers display them when an image fails to load, and search engines use them to understand what the picture shows.

Why alt text matters

Alt text does double duty. For accessibility, it's how someone using a screen reader knows what an image conveys — often a legal requirement under standards like WCAG and, in Canada, the AODA. For SEO, it gives search engines context they can't get from pixels alone, which helps images rank in Google Images and reinforces the page's topic. When a connection is slow or a file breaks, the alt text also shows in the image's place.

How to write effective alt text

Describe the image as if reading the page aloud to someone who can't see it: specific, concise, no keyword stuffing. Compare three versions of the same product photo:

• Weak: alt="shoe" — accurate but useless.
• Better: alt="red Salomon trail running shoe, side view" — specific and descriptive.
• Overdone: alt="running shoe trail shoe best shoes buy shoes cheap shoes" — reads as spam and can hurt you.

A few rules keep it clean: skip "image of" since screen readers already announce it, leave decorative images' alt empty so they're skipped, and include any text baked into an image so it isn't lost. Alt text is a small but genuine part of on-page SEO and overall user experience.