Viewing all the timeouts/intervals in javascript?

I don't think there is a way to enumerate active timers, but you could override window.setTimeout and window.clearTimeout and replace them with your own implementations which do some tracking and then call the originals.

window.originalSetTimeout = window.setTimeout;window.originalClearTimeout = window.clearTimeout;window.activeTimers = 0;window.setTimeout = function(func, delay) {    window.activeTimers++;    return window.originalSetTimeout(func, delay);};window.clearTimeout = function(timerID) {    window.activeTimers--;    window.originalClearTimeout(timerID);};

Of course, you might not always call clearTimeout, but this would at least give you some way to track what is happening at runtime.

I made a Chrome DevTools extension that shows all intervals. Cleared ones are greyed out.

setInterval-sniffer

Instead of just have a count of timers, here is an implementation which stores all timerid's into an array. It only shows active timers while the accepted answer only counts calls to setTimeout & clearTimeout.

(function(w) {    var oldST = w.setTimeout;    var oldSI = w.setInterval;    var oldCI = w.clearInterval;    var timers = [];    w.timers = timers;    w.setTimeout = function(fn, delay) {        var id = oldST(function() {            fn && fn();            removeTimer(id);        }, delay);        timers.push(id);        return id;    };    w.setInterval = function(fn, delay) {        var id = oldSI(fn, delay);        timers.push(id);        return id;    };    w.clearInterval = function(id) {        oldCI(id);        removeTimer(id);    };    w.clearTimeout = w.clearInterval;    function removeTimer(id) {        var index = timers.indexOf(id);        if (index >= 0)            timers.splice(index, 1);    }}(window));

This is how you can get the count of active timers on the page:

timers.length;

This is how you can remove all active timers:

for(var i = timers.length; i--;)    clearInterval(timers[i]);

Known limitations:

• You can only pass a function (not a string) to setTimeout with this monkey patch.
• The function assumes clearInterval and clearTimeout do the same, which they do but it could change in the future.