I've never read the HTML spec directly until checking it now to verify your comment. I usually use MDN, which says that the alt attribute is not mandatory. [1]

I've never read the HTML spec directly until checking it now to verify your comment. I usually use MDN, which says that the alt attribute is not mandatory. [1] [1] https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Img https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Im...