CSS Font Loading
This CSS module defines a scripting interface to font faces in CSS, allowing font faces to be easily created and loaded from script. It also provides methods to track the loading status of an individual font, or of all the fonts on an entire page.
API that can be used to understand the visibility and position of DOM elements relative to a containing element or to the top-level viewport. The position is delivered asynchronously and is useful for understanding the visibility of elements and implementing pre-loading and deferred loading of DOM content.
Resource Hints: Lazyload
Gives a hint to the browser to lower the loading priority of a resource. Please note that this is a legacy attribute, see the [`loading`](https://caniuse.com/#feat=loading-lazy-attr) attribute for the new standardized API.
Lazy loading via attribute for images & iframes
The `loading` attributing on images & iframes gives authors control over when the browser should start loading the resource.
FontFaceSet API: onloading
FontFaceSet API: onloadingdone
FontFaceSet API: onloadingerror
HTMLImageElement API: loading
PerformanceTiming API: domLoading
HTML element: iframe: loading
HTML element: img: loading