Another reason is that if you're using an image as a link, the alt text for that image will be treated similarly to the anchor text of a text link. However, we don't recommend using too many images for links in your site's navigation when text links could serve the same purpose. Lastly, optimizing your image filenames and alt text makes it easier for image search projects like Google Image Search to better understand your images.
In the last year, Google and Bing have both indicated a shift to entity-based search results as part of their evolution. Google has unscored this point with rich snippets and Knowledge Graph, and Bing has now upped the ante on personal search results with Bing Snapshots. Find out how you can adopt strategies to stay ahead of the curve in the new world of semantic search results.
It might be awkward, but please don't scroll past this. This Monday we humbly ask you to defend Wikipedia's independence. Our 2019 fundraiser will be over very soon. 98% of our readers don't give; they look the other way. If you are an exceptional reader who already donated, we sincerely thank you. If all our readers donated just $2.75 today, Wikipedia could keep thriving for years. Most people donate for a simple reason—because Wikipedia is useful. If Wikipedia gave you $2.75 worth of knowledge this year, take a minute to secure its future with a gift to the Wikimedia Endowment. Show the volunteers who bring you reliable, neutral information that their work matters. Thank you.