HTMLFencedFrameElement: config property

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The config property of the HTMLFencedFrameElement contains a FencedFrameConfig object, which represents the navigation of a <fencedframe>, i.e. what content will be displayed in it. A FencedFrameConfig is returned from a source such as the Protected Audience API.


The value of config is initially null.

When its value is set to a FencedFrameConfig object instance, the FencedFrameConfig's internal properties (for example mappedURL) determine what is loaded inside the associated <fencedframe>. In addition:

  • The navigation type will be "replace" (see NavigateEvent.navigationType), meaning that the current history entry is replaced with the new entry, rather adding a new history entry for it.
  • The navigation's Referrer-Policy is set to "no-referrer".


To set what content will be shown in a <fencedframe>, a utilizing API (such as Protected Audience or Shared Storage) generates a FencedFrameConfig object, which is then set as the value of the <fencedframe>'s config property.

The following example gets a FencedFrameConfig from a Protected Audience API's ad auction, which is then used to display the winning ad in a <fencedframe>:

const frameConfig = await navigator.runAdAuction({
  // configuration
  resolveToConfig: true,

const frame = document.createElement("fencedframe");
frame.config = frameConfig;

Note: resolveToConfig: true must be passed in to the runAdAuction() call to obtain a FencedFrameConfig object. If it is not set, the resulting Promise will resolve to a URN that can only be used in an <iframe>.


Fenced Frame
# dom-htmlfencedframeelement-config

Browser compatibility

BCD tables only load in the browser

See also