HTMLIFrameElement: browsingTopics property
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.
Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
Warning: This feature is currently opposed by two browser vendors. See the Standards positions section for details of opposition.
The browsingTopics property of the HTMLIFrameElement interface is a boolean specifying that the selected topics for the current user should be sent with the request for the associated <iframe>'s source in a Sec-Browsing-Topics header. This reflects the browsingtopics HTML attribute.
See Using the Topics API for more details.
Value
A boolean. The default value is false; set it to true to send the associated <iframe> source request with a Sec-Browsing-Topics header containing the selected topics for the current user.
Examples
Get
Set browsingtopics to true then load the <iframe> contents declaratively:
<iframe browsingtopics title="Advertising container" src="ad-tech1.example">
...
</iframe>
Log the browsingTopics value via script:
const iframeElem = document.querySelector("iframe");
console.log(iframeElem.browsingTopics); // will return true in supporting browsers
Set
Specify a minimum <iframe>:
<iframe> ... </iframe>
Set browsingtopics to true then load the <iframe> contents via script:
const iframeElem = document.querySelector("iframe");
iframeElem.browsingTopics = true;
iframeElem.title = "Advertising container";
iframeElem.src = "ad-tech1.example";
Specifications
This feature is not part of an official standard, although it is specified in the Topics API Unofficial Proposal Draft.