[javascript] How to get height of entire document with JavaScript?

Full Document height calculation:

To be more generic and find the height of any document you could just find the highest DOM Node on current page with a simple recursion:

;(function() {
    var pageHeight = 0;

    function findHighestNode(nodesList) {
        for (var i = nodesList.length - 1; i >= 0; i--) {
            if (nodesList[i].scrollHeight && nodesList[i].clientHeight) {
                var elHeight = Math.max(nodesList[i].scrollHeight, nodesList[i].clientHeight);
                pageHeight = Math.max(elHeight, pageHeight);
            }
            if (nodesList[i].childNodes.length) findHighestNode(nodesList[i].childNodes);
        }
    }

    findHighestNode(document.documentElement.childNodes);

    // The entire page height is found
    console.log('Page height is', pageHeight);
})();

You can Test it on your sample sites (http://fandango.com/ or http://paperbackswap.com/) with pasting this script to a DevTools Console.

NOTE: it is working with Iframes.

Enjoy!