Alt Attributes
The primary purpose of alt attributes is to provide a description of a particular image for those cases when users can’t see the said image. As a rule, this happens when people view your website with text-only browsers or if there are some problems with the Internet connection or the image file. However, the use of alt attributes is more than just a good UX practice.
SEO-wise, there are two reasons to give alt attributes a proper consideration:
Just like with any other element of your page, you wouldn’t want to stuff your alt attributes with keywords. Instead, provide a comprehensive description that will prove useful for your audience. For instance, an alt attribute text for a product image may include the product name, price, and other details. Follow the recommendations from Yoast to learn more about alt attributes and the optimization of images.