What is an alt tag and how does it affect SEO?
Definition: An alt tag, also known as an “alt attribute”, is an HTML attribute applied to image tags to provide a textual alternative to search engines. Applying alt tags to images, such as product photos, can positively affect your SERP.
What is the purpose of alt tags?
Search engines and other robots cannot interpret or understand the meaning of images although images can play a crucial role in the way a particular website is interpreted. Alt tags address this by providing a textual description that search engines can understand. When Googlebot or other crawlers browse the page, images with properly formatted alt text help to better index the page and give it a better place in search results.
In that sense, alt text offers you another opportunity to include your target keyword. With on-page keyword usage still pulling weight as a search engine ranking factor, it’s in your best interest to create alt text that both describes the image and, if possible, includes a keyword or keyword phrase you’re targeting.
Alt tags are also useful for users who view the webpage on screen readers or browsers that cannot process images.