Iframe without src but still has content?

May 12, 2023 by Tarik

Yes, it is possible to load an empty <iframe> (with no src specified) and later apply content to it using script.

See: http://api.jquery.com/jquery-wp-content/themes/jquery/js/main.js (line 54 and below).

Or simply try:

<iframe></iframe>

<script>
document.querySelector('iframe')
        .contentDocument.write("<h1>Injected from parent frame</h1>")
</script>