Fence: getNestedConfigs() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

See full compatibility

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

The getNestedConfigs() method of the Fence interface returns the FencedFrameConfigs loaded into <fencedframe>s embedded inside the current <fencedframe>.

Syntax

getNestedConfigs()

Parameters

None.

Return value

getNestedConfigs() has two possible return values:

An array of 20 FencedFrameConfig objects, if the current <fencedframe>'s config was created using an API that supports nested configs (for example Protected Audience). Of these 20 configs, the first N configs are those registered through the API and the rest are padding configs that will navigate to about:blank, so that the number of configs is hidden and cannot leak any information.
null if the current <fencedframe>'s config was created using an API that does not support nested configs (for example Shared Storage).

Examples

// Run inside a <fencedframe>

// Retrieve the configs of embedded fenced frames
const configs = window.fence.getNestedConfigs();

// Set a new fenced frame's config to equal one of the retrieved configs
const frame = document.createElement("fencedframe");
frame.config = configs[0];

Specifications

Specification
Fenced Frame # dom-fence-getnestedconfigs

Browser compatibility

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`getNestedConfigs` Experimental	Chrome – Full support Chrome 126 (Release date: 2024-06-11) footnote Full support	Edge – Full support Edge 126 (Release date: 2024-06-13) footnote Full support	Firefox – No support Firefox footnote No support	Opera – Full support Opera 112 (Release date: 2024-07-11) footnote Full support	Safari – No support Safari footnote No support	Chrome Android – Full support Chrome Android 126 (Release date: 2024-06-11) footnote Full support	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 83 (Release date: 2024-06-25) footnote Full support	Safari on iOS – No support Safari on iOS footnote No support	Samsung Internet – Full support Samsung Internet 28 (Release date: 2025-04-02) footnote Full support	WebView Android – Full support WebView Android 126 (Release date: 2024-06-11) footnote Full support	WebView on iOS – No support WebView on iOS footnote No support

Tip: you can click/tap on a cell for more information.

Full support: Full support
No support: No support
: Experimental. Expect behavior to change in the future.