What is data-cfsrc in HTML

Question

What is data-cfsrc attribute of HTML ??

I got it inside an img tag.

Thanks

Answer 1

As Mike W says, any attribute starting data- is an arbitrary data string attached to any element. The data-cfsrc is used by CloudFlare's Mirage feature to lazy-load images to improve website performance.

Answer 2

Any attribute starting data- is an arbitrary data string attached to any element. It can be queried bt Javascript for whatever purpose the designer has in mind.