Why it exists
Alt text makes images accessible to people who can't see them. Web accessibility guidelines (WCAG) require text alternatives for meaningful images, and screen reader users rely on alt text to follow a page.
How it helps SEO
Search engines can't fully see images, so they use alt text, file names and surrounding text to understand them. Good alt text helps images appear in image search and supports the page's relevance.
How to write it
Describe what the image shows and why it matters on that page, in a short, natural sentence. A product photo might read 'Black leather office chair with adjustable armrests', not 'chair image' or a list of keywords.
Why Alt Text matters
Missing or poor alt text shuts out visitors who use screen readers and can create accessibility risk. It also wastes a simple chance to help search engines understand your images and products.
From 'IMG_2041' to useful
An online store's product images all had alt text like 'image' or the original file name. Rewriting them to describe each product, color and key feature made the catalog usable with a screen reader and gave image search something real to index.
Common mistakes
Keyword stuffing
Alt text packed with keywords reads badly for screen reader users and can look like spam to search engines. Describe the image naturally.
Describing decorative images
Purely decorative images, like background shapes, should have empty alt text (alt="") so screen readers skip them.
Starting with 'image of'
Screen readers already announce that it's an image. Get straight to the description.
Where we work on this