How to clear the content of an IFRAME?

How do I clear the content of my IFRAME element, using javascript, without loading a blank page into it?

I can figure out to do this: iframe_element.src = "blank.html", but there must be a better, instant, method.

about:blank

is a "URL" that is blank. It's always clear

You can set the page's source to that, and it will clear.

var iframe = document.getElementById("myiframe");
var html = "";

iframe.contentWindow.document.open();
iframe.contentWindow.document.write(html);
iframe.contentWindow.document.close();

tested in IE, Firefox and Chrome ... it did it :)

Your technique is the most robust. Its the one I use myself. At times content may be delivered over HTTPS and the use of about:blank can cause warning messages to appear to the effect of "do you want to include content from unsecure location" or some such thing.

Something being instant is a matter of perception however if you have a single Blank.html file on your site configured with a long cache expiry the client will only ever fetch the page once (at the most once per-session).

Or you can do this :

var iframe_element = window.frames['iframe_name'];
iframe_element.document.open();
iframe_element.document.close();

I have had difficulties with "about:blank" on pages with many IFrames. It does not seem to be a valid location in every browser (I never found out for sure, though). Anyway, I am happy with javascript:void(0);