On Twitter, Google’s John Mueller said that the image alt text is extremely helpful for Google Images. If you want to get ranked in Google images, you should make sure that your images have a descriptive image alt attribute:
Alt text is extremely helpful for Google Images — if you want your images to rank there. Even if you use lazy-loading, you know which image will be loaded, so get that information in there as early as possible & test what it renders as.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) 4. September 2018
How to check the image alt texts on your web pages
Among many other things, the website audit tool in SEOprofiler checks the image alt texts on your web pages. You can create your free SEOprofiler account here: