---
category: Watch
alias: throttledWatch
---

# watchThrottled

Throttled watch.

## Usage

Similar to `watch`, but offering an extra option `throttle` which will be applied to the callback function.

```ts
import { watchThrottled } from '@vueuse/core';

watchThrottled(
  source,
  () => {
    console.log('changed!');
  },
  { throttle: 500 },
);
```

It's essentially a shorthand for the following code:

```ts
import { throttleFilter, watchWithFilter } from '@vueuse/core';

watchWithFilter(
  source,
  () => {
    console.log('changed!');
  },
  {
    eventFilter: throttleFilter(500),
  },
);
```

## Type Declarations

```ts
export interface WatchThrottledOptions<Immediate> extends WatchOptions<Immediate> {
  throttle?: MaybeRefOrGetter<number>;
  trailing?: boolean;
  leading?: boolean;
}
export declare function watchThrottled<
  T extends Readonly<MultiWatchSources>,
  Immediate extends Readonly<boolean> = false,
>(
  sources: [...T],
  cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
  options?: WatchThrottledOptions<Immediate>,
): WatchHandle;
export declare function watchThrottled<T, Immediate extends Readonly<boolean> = false>(
  source: WatchSource<T>,
  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
  options?: WatchThrottledOptions<Immediate>,
): WatchHandle;
export declare function watchThrottled<
  T extends object,
  Immediate extends Readonly<boolean> = false,
>(
  source: T,
  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
  options?: WatchThrottledOptions<Immediate>,
): WatchHandle;
/** @deprecated use `watchThrottled` instead */
export declare const throttledWatch: typeof watchThrottled;
```