HTMLIFrameElement: contentDocument property

If the iframe and the iframe's parent document are Same Origin, returns a Document (that is, the active document in the inline frame's nested browsing context), else returns null.

Example of contentDocument

js
const iframeDocument = document.querySelector("iframe").contentDocument;

iframeDocument.body.style.backgroundColor = "blue";
// This would turn the iframe blue.

Specifications

Specification
HTML Standard
# dom-iframe-contentdocument

Browser compatibility

Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
contentDocument