Alt Text (Alternative Text)

Definition

Alt text (alternative text) is an HTML attribute added to image tags that describes the image content. It serves two critical purposes: accessibility (screen readers read alt text aloud for visually impaired users) and SEO (search engines use alt text to understand what an image depicts). Good alt text is concise, descriptive, and naturally includes relevant keywords when appropriate. Best practices: describe the image content accurately, keep it under 125 characters, avoid starting with 'image of' or 'picture of', include target keywords naturally (not forced), and leave decorative images with empty alt attributes (alt=""). Alt text is also displayed when images fail to load.