1---
2category: Utilities
3related: refThrottled, refDebounced, useDebounceFn
4---
5 
6# useThrottleFn
7 
8Throttle execution of a function. Especially useful for rate limiting execution of handlers on events like resize and scroll.
9 
10> Throttle is a spring that throws balls: after a ball flies out it needs some time to shrink back, so it cannot throw any more balls unless it's ready.
11 
12## Usage
13 
14```ts
15import { useThrottleFn } from '@vueuse/core'
16 
17const throttledFn = useThrottleFn(() => {
18  // do something, it will be called at most 1 time per second
19}, 1000)
20 
21useEventListener(window, 'resize', throttledFn)
22```
23 
24## Recommended Reading
25 
26- [**Debounce vs Throttle**: Definitive Visual Guide](https://kettanaito.com/blog/debounce-vs-throttle)
27 
28## Type Declarations
29 
30```ts
31/**
32 * Throttle execution of a function. Especially useful for rate limiting
33 * execution of handlers on events like resize and scroll.
34 *
35 * @param   fn             A function to be executed after delay milliseconds. The `this` context and all arguments are passed through, as-is,
36 *                                    to `callback` when the throttled-function is executed.
37 * @param   ms             A zero-or-greater delay in milliseconds. For event callbacks, values around 100 or 250 (or even higher) are most useful.
38 *                                    (default value: 200)
39 *
40 * @param [trailing] if true, call fn again after the time is up (default value: false)
41 *
42 * @param [leading] if true, call fn on the leading edge of the ms timeout (default value: true)
43 *
44 * @param [rejectOnCancel] if true, reject the last call if it's been cancel (default value: false)
45 *
46 * @return  A new, throttled, function.
47 *
48 * @__NO_SIDE_EFFECTS__
49 */
50export declare function useThrottleFn<T extends FunctionArgs>(
51  fn: T,
52  ms?: MaybeRefOrGetter<number>,
53  trailing?: boolean,
54  leading?: boolean,
55  rejectOnCancel?: boolean,
56): PromisifyFn<T>
57```
58