Some thoughts on HTML's proposed previewsrc attribute

One of the great things about modern HTML is that it tries to standardise stuff that developers are already doing. If there are a myriad ways of, for example, loading video onto a page - then browsers and other interested parties should work out how to make a standard <video> element. An interesting new proposal has been brought forth by Microsoft. There are a dozen ways to show a preview of an <img> element before the src= attribute has loaded. So why not standardise on previewsrc=? There's an excellent explainer on Patrick Brosset's blog. I instinctively like the idea - if only to simplify source code and reduce JS usage. But I do have some concerns which I've shared with the team. What's The User Need? This is the thing I always bang on about when I'm discussing standards. Additions to HTML should primarily benefit end users, not developers. Do end users want this? Is there a bunch of research that shows normal people are confused that they don't see a preview image? Do they recoil…