1---
2category: Watch
3alias: debouncedWatch
4---
5 
6# watchDebounced
7 
8Debounced watch. The callback will only be invoked after the source stops changing for the specified duration.
9 
10## Usage
11 
12Similar to `watch`, but offering extra options `debounce` and `maxWait` which will be applied to the callback function.
13 
14```ts
15import { watchDebounced } from '@vueuse/core'
16 
17watchDebounced(
18  source,
19  () => { console.log('changed!') },
20  { debounce: 500, maxWait: 1000 },
21)
22```
23 
24### Options
25 
26| Option     | Type                       | Default | Description                                |
27| ---------- | -------------------------- | ------- | ------------------------------------------ |
28| `debounce` | `MaybeRefOrGetter<number>` | `0`     | Debounce delay in ms (can be reactive)     |
29| `maxWait`  | `MaybeRefOrGetter<number>` | —       | Maximum wait time before forced invocation |
30 
31All standard `watch` options (`deep`, `immediate`, `flush`, etc.) are also supported.
32 
33### Reactive Debounce Time
34 
35The debounce time can be reactive:
36 
37```ts
38import { watchDebounced } from '@vueuse/core'
39 
40const debounceMs = ref(500)
41 
42watchDebounced(
43  source,
44  () => { console.log('changed!') },
45  { debounce: debounceMs },
46)
47 
48// Later, change the debounce time
49debounceMs.value = 1000
50```
51 
52## How It Works
53 
54It's essentially a shorthand for the following code:
55 
56```ts
57import { debounceFilter, watchWithFilter } from '@vueuse/core'
58 
59watchWithFilter(
60  source,
61  () => { console.log('changed!') },
62  {
63    eventFilter: debounceFilter(500, { maxWait: 1000 }),
64  },
65)
66```
67 
68## Type Declarations
69 
70```ts
71export interface WatchDebouncedOptions<Immediate>
72  extends WatchOptions<Immediate>, DebounceFilterOptions {
73  debounce?: MaybeRefOrGetter<number>
74}
75export declare function watchDebounced<
76  T extends Readonly<MultiWatchSources>,
77  Immediate extends Readonly<boolean> = false,
78>(
79  sources: [...T],
80  cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
81  options?: WatchDebouncedOptions<Immediate>,
82): WatchHandle
83export declare function watchDebounced<
84  T,
85  Immediate extends Readonly<boolean> = false,
86>(
87  source: WatchSource<T>,
88  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
89  options?: WatchDebouncedOptions<Immediate>,
90): WatchHandle
91export declare function watchDebounced<
92  T extends object,
93  Immediate extends Readonly<boolean> = false,
94>(
95  source: T,
96  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
97  options?: WatchDebouncedOptions<Immediate>,
98): WatchHandle
99/** @deprecated use `watchDebounced` instead */
100export declare const debouncedWatch: typeof watchDebounced
101```
102