On-page SEO
Alt Text
Last updated
What is Alt Text?
Alt text (alternative text) is an HTML attribute added to image tags that describes the visual content of an image in words. It serves two primary purposes: providing context to search engine crawlers that cannot "see" images, and improving accessibility for users relying on screen readers or when images fail to load. Well-written alt text is concise, descriptive, and contextually relevant.
From an SEO perspective, alt text is an opportunity to include keywords naturally while helping search engines understand what an image depicts. Images with descriptive alt text can rank in Google Image Search, driving additional organic traffic. Decorative images that add no informational value should use an empty alt attribute (`alt=""`) so screen readers skip them.
Why it matters for SEO
Alt text improves image discoverability in search engines and contributes to overall page relevance signals. It also supports web accessibility compliance, which is increasingly considered a factor in user experience scores that influence rankings.
Example
On a recipe blog, an image tag reads <img src="IMG_2041.jpg" alt="image">. Changing it to alt="Slice of lemon drizzle cake on a white plate with a fork" describes what the picture shows for screen-reader users and gives search engines context for image search. A purely decorative divider graphic on the same page keeps an empty alt="" so assistive technology skips it.
Go further with Alt Text
Put the theory to work
LazySEO researches keywords, writes SEO articles and publishes them to your site on a schedule.