Reload an IFRAME without adding to the history

Like Greg said above, the .replace() function is how to do this. I can't seem to figure out how to reply to his answer*, but the trick is to reference the iFrames contentWindow property.

var ifr = document.getElementById("iframeId");
ifr.contentWindow.location.replace("newLocation.html"); 

*Just learned I need more reputation to comment on an answer.

You can use javascript location.replace:

window.location.replace('...html');

Replace the current document with the one at the provided URL. The difference from the assign() method is that after using replace() the current page will not be saved in session history, meaning the user won't be able to use the Back button to navigate to it.

Using replace() is only an option with your own domain iframes. It fails to work on remote sites (eg: a twitter button) and requires some browser-specific knowledge to reliably access the child window.

Instead, just remove the iframe element and construct a new one in the same spot. History items are only created when you modify the src attribute after it is in the DOM, so make sure to set it before the append.

Edit: JDandChips rightly mentions that you can remove from DOM, modifiy, and re-append. Constructing fresh is not required.

An alternative method to recreating the iframe would be to remove the iframe from the DOM, change the src and then re add it.

In many ways this is similar to the replace() suggestion, but I had some issues when I tried that approach with History.js and managing states manually.

var container = iframe.parent();

iframe.remove();
iframe.attr('src', 'about:blank');

container.append(iframe);