---
category: Reactivity
related: syncRef
---

# syncRefs

Keep target refs in sync with a source ref

## Usage

```ts
import { syncRefs } from '@vueuse/core';
import { shallowRef } from 'vue';

const source = shallowRef('hello');
const target = shallowRef('target');

const stop = syncRefs(source, target);

console.log(target.value); // hello

source.value = 'foo';

console.log(target.value); // foo
```

### Sync with multiple targets

You can also pass an array of refs to sync.

```ts
import { syncRefs } from '@vueuse/core';
import { shallowRef } from 'vue';

const source = shallowRef('hello');
const target1 = shallowRef('target1');
const target2 = shallowRef('target2');

const stop = syncRefs(source, [target1, target2]);

console.log(target1.value); // hello
console.log(target2.value); // hello

source.value = 'foo';

console.log(target1.value); // foo
console.log(target2.value); // foo
```

## Watch options

The options for `syncRefs` are similar to `watch`'s `WatchOptions` but with different default values.

```ts
export interface SyncRefOptions {
  /**
   * Timing for syncing, same as watch's flush option
   *
   * @default 'sync'
   */
  flush?: WatchOptionFlush;
  /**
   * Watch deeply
   *
   * @default false
   */
  deep?: boolean;
  /**
   * Sync values immediately
   *
   * @default true
   */
  immediate?: boolean;
}
```

When setting `{ flush: 'pre' }`, the target reference will be updated at [the end of the current "tick"](https://vuejs.org/guide/essentials/watchers.html#callback-flush-timing) before rendering starts.

```ts
import { syncRefs } from '@vueuse/core';
import { nextTick, shallowRef } from 'vue';

const source = shallowRef('hello');
const target = shallowRef('target');

syncRefs(source, target, { flush: 'pre' });

console.log(target.value); // hello

source.value = 'foo';

console.log(target.value); // hello <- still unchanged, because of flush 'pre'

await nextTick();

console.log(target.value); // foo <- changed!
```

## Type Declarations

```ts
export interface SyncRefsOptions extends ConfigurableFlushSync {
  /**
   * Watch deeply
   *
   * @default false
   */
  deep?: boolean;
  /**
   * Sync values immediately
   *
   * @default true
   */
  immediate?: boolean;
}
/**
 * Keep target ref(s) in sync with the source ref
 *
 * @param source source ref
 * @param targets
 */
export declare function syncRefs<T>(
  source: WatchSource<T>,
  targets: Ref<T> | Ref<T>[],
  options?: SyncRefsOptions,
): WatchHandle;
```
