_.debounce(func, [wait=0], [options={}])

source npm package

Creates a debounced function that delays invoking func until after wait milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a cancelmethod to cancel delayed func invocations and a flush method to immediately invoke them. Provide options to indicate whether func should be invoked on the leading and/or trailing edge of the waittimeout. The func is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last func invocation.

Note: If leading and trailing options are truefunc is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the wait timeout.

If wait is 0 and leading is falsefunc invocation is deferred until to the next tick, similar to setTimeout with a timeout of 0.

See David Corbacho’s article for details over the differences between _.debounce and _.throttle.




  1. func (Function): The function to debounce.
  2. [wait=0] (number): The number of milliseconds to delay.
  3. [options={}] (Object): The options object.
  4. [options.leading=false] (boolean): Specify invoking on the leading edge of the timeout.
  5. [options.maxWait] (number): The maximum time func is allowed to be delayed before it’s invoked.
  6. [options.trailing=true] (boolean): Specify invoking on the trailing edge of the timeout.


(Function): Returns the new debounced function.


// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));
// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);
// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);