Javascript – How to detect if document has loaded (IE 7/Firefox 3)

There’s no need for all the code mentioned by galambalazs. The cross-browser way to do it in pure JavaScript is simply to test document.readyState:

if (document.readyState === "complete") { init(); }

This is also how jQuery does it.

Depending on where the JavaScript is loaded, this can be done inside an interval:

var readyStateCheckInterval = setInterval(function() {
    if (document.readyState === "complete") {
        clearInterval(readyStateCheckInterval);
        init();
    }
}, 10);

In fact, document.readyState can have three states:

Returns “loading” while the document is loading, “interactive” once it is finished parsing but still loading sub-resources, and “complete” once it has loaded.
document.readyState at Mozilla Developer Network

So if you only need the DOM to be ready, check for document.readyState === "interactive". If you need the whole page to be ready, including images, check for document.readyState === "complete".

Leave a Comment