HTML <iframe> fetchpriority Attribute

Note: This attribute is Experimental.

<iframe src="https://www.youtube.com/embed/KrM107U_uRg" fetchpriority="high">
  Your browser does not support iframe element.
</iframe>

Meaning

The fetchpriority attribute provides a hint of the relative priority to use when fetching the iframe document.

<iframe fetchpriority="high|low|auto">

Value	Description
high	Signals a high-priority fetch relative to other iframe documents.
low	Signals a low-priority fetch relative to other iframe documents.
auto	Default: Signals automatic determination of fetch priority relative to other iframe documents.