function resizeIframe(obj){ obj.contentWindow.postMessage({action: 'getDocumentHeight', targetElementId: obj.id}, '*'); } window.addEventListener('message', function (event) { document.getElementById(event.data.targetElementId).style.height = (event.data.documentHeight + 35) + 'px'; }); document.addEventListener("DOMContentLoaded", function(event) { var ifrm = document.createElement('iframe'); ifrm.setAttribute('id', 'widget-iframe-7065'); ifrm.setAttribute('width', '100%'); ifrm.setAttribute('height', '0'); ifrm.setAttribute('scrolling', 'no'); ifrm.frameBorder=0; ifrm.setAttribute('onload', 'resizeIframe(this)'); var el = document.getElementById('3'); el.appendChild(ifrm); ifrm.setAttribute('src', 'https://rankingi.rp.pl/widget/builder?token=62b33d19bc5fc278f8c4cb82f0c2fb6a49a813e713e93ca3c3a79'); });