window.onload vs. body.onload vs. document.onready

Question

What is the difference between window.onload, document.onready and body.onload ?

[This](http://stackoverflow.com/questions/191157/window-onload-vs-body-onload) will help you... Best of luck! :) — PHP, Aug 13 '10 at 05:07
Why was this marked as a duplicate? This doesn't even mention jQuery, while the other has it in the title (`ready` is jQuery only). — Ciro Santilli OurBigBook.com, Jun 13 '14 at 09:51
Aggree with Ciro. Far too many people on StackOverflow think that JavaScript === jQuery. — Seanonymous, Aug 26 '15 at 18:31
Probably because having jQuery wrapped around it makes no difference to what the different events mean. — Quentin, Sep 14 '15 at 15:12

alex · Accepted Answer · 2011-12-01T02:40:54.400

67

window.onload will wait until all assets have finished downloading, such as images and scripts.

DOM ready waits until you can access the DOM via the API.

As a side note, in this day and age, you ought to be using window.addEventListener('load', function() { }, false) or attachEvent() for older IEs.

edited Dec 01 '11 at 02:40

answered Aug 13 '10 at 05:14

alex

1

I think the DOM ready functionality of jQuery would also wait for scripts to load before firing wouldn't it? – screenm0nkey Apr 06 '11 at 13:52
But it cannot work for Chrome, Safari and Opera. Is there an alternative of `window.onload` for those browsers? – william Dec 01 '11 at 02:27
3

@william: `window.addEventListener('load', function() { }, false)`. – alex Dec 01 '11 at 02:40
Yes. `DOMContentLoaded` event from memory. – alex Aug 12 '12 at 01:18
What you mean by "in this day and age" is that it should be acceptable to defer script execution to onload on IE8 (since IE6-7 are more or less a thing of the past)? – Camilo Martin Oct 03 '12 at 17:35
@CamiloMartin I mean use the event handler systems besides `onevent` properties. – alex Dec 14 '12 at 11:27
@HiroProtagonist document.readyState and DOMContentLoaded are native to JavaScript – Christophe Feb 07 '13 at 17:55
Note that this won't let you know when the contents of an iFrame have loaded :) http://stackoverflow.com/questions/20572734/load-event-not-firing-when-iframe-is-loaded-in-chrome – Dean Rather Aug 04 '15 at 03:13

1 Answers1