document.querySelectorAll('body a').forEach((val) => { let linkCheck = new RegExp('/' + window.location.host + '/') if (!linkCheck.test(val.href)) { let currentRel = val.getAttribute('rel') val.setAttribute('target', '_blank') if (currentRel) { val.setAttribute('rel', 'noreferrer noopener ' + val.getAttribute('rel')) } else { val.setAttribute('rel', 'noreferrer noopener') } } }) //Replace 'body a' with desired selector