Viewing all the timeouts/intervals in javascript?

I'm writing an application that utilizes JavaScript timeouts and intervals to update the page. Is there a way to see how many intervals are setup? I want to make sure that I'm not accidentally going to kill the browser by having hundreds of intervals setup.

Is this even an issue?

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