 <p>The display issue is caused by the Editor that outputs the iframe with size "width: 0px". </p> <p>Next step, finding a possible <strong>solution</strong>:</p> <p><strong>CSS</strong> Set a predefined width for all Iframes, example [CSS][1];</p> <p>OR</p> <p><strong>Jquery</strong> (Example: [change-iframe-width-and-height-using-jquery][2])</p> <pre><code>[1]: http://jsfiddle.net/7WRHM/1001/ [2]: http://stackoverflow.com/a/14913861/2842657 </code></pre> <p><strong><em>I have not tested thoroughly but this solution seems to solve the issue</em></strong>: </p> <pre><code>.cke_contents &gt; iframe{ width: 100% !important; } </code></pre>