Alt text (alternative text) is a short written description added to an image’s HTML code. It serves two main purposes: it describes the image to visually impaired users relying on screen readers, and it helps search engines understand what an image depicts, since they can’t “see” images the way humans do.
From an SEO perspective, well-written alt text can help images rank in Google Image Search and gives search engines additional context about the overall content and relevance of the page they’re on.
Effective alt text is descriptive and specific rather than generic, avoids keyword stuffing, and reads naturally — as if you were describing the image to someone who couldn’t see it.
Image optimization, including alt text, is covered as part of our On-Page SEO service.