I have a file browser application I want to integrate into an iframe of a main website. To adjust the scroll height of the iframte to the content I use following code: iframecontent: window.top.postMessage({ height: document.body.scrollHeight }, "*"); main site html: <iframe id="iframe1" src="https://mysubfilebrowser.com&quot; frameborder="0" scrolling="no" width="100%" height="10000"> Your browser doesn’t support iframes </iframe> <script>… Read More Performance Problems with JS postMessage to adjust parent iframe scrollHeight