Inspect attached event handlers for any DOM element

Event handlers attached using traditional element.onclick= handler or HTML <element onclick="handler"> can be retrieved trivially from the element.onclick property from script or in-debugger.

Event handlers attached using DOM Level 2 Events addEventListener methods and IE's attachEvent cannot currently be retrieved from script at all. DOM Level 3 once proposed element.eventListenerList to get all listeners, but it is unclear whether this will make it to the final specification. There is no implementation in any browser today.

A debugging tool as browser extension could get access to these kinds of listeners, but I'm not aware of any that actually do.

Some JS frameworks leave enough of a record of event binding to work out what they've been up to. Visual Event takes this approach to discover listeners registered through a few popular frameworks.

The Elements Panel in Google Chrome Developer tools has had this since Chrome releases in mid 2011 and Chrome developer channel releases since 2010.

Also, the event listeners shown for the selected node are in the order in which they are fired through the capturing and bubbling phases.

Hit command + option + i on Mac OSX and Ctrl + Shift + i on Windows to fire this up in Chrome