useFocus 
Reactive utility to track or set the focus state of a DOM element. State changes to reflect whether the target element is the focused element. Setting reactive value from the outside will trigger focus and blur events for true and false values respectively.
Demo 
Paragraph that can be focused
 The input control has focus 
Basic Usage 
ts
import { useFocus } from '@vueuse/core'
const target = ref()
const { focused } = useFocus(target)
watch(focused, (focused) => {
  if (focused)
    console.log('input element has been focused')
  else console.log('input element has lost focus')
})Setting initial focus 
To focus the element on its first render one can provide the initialValue option as true. This will trigger a focus event on the target element.
ts
import { useFocus } from '@vueuse/core'
const target = ref()
const { focused } = useFocus(target, { initialValue: true })Change focus state 
Changes of the focused reactive ref will automatically trigger focus and blur events for true and false values respectively. You can utilize this behavior to focus the target element as a result of another action (e.g. when a button click as shown below).
vue
<script>
import { ref } from 'vue'
import { useFocus } from '@vueuse/core'
export default {
  setup() {
    const input = ref()
    const { focused } = useFocus(input)
    return {
      input,
      focused,
    }
  }
}
</script>
<template>
  <div>
    <button type="button" @click="focused = true">
      Click me to focus input below
    </button>
    <input ref="input" type="text">
  </div>
</template>Type Declarations 
typescript
export interface UseFocusOptions extends ConfigurableWindow {
  /**
   * Initial value. If set true, then focus will be set on the target
   *
   * @default false
   */
  initialValue?: boolean
  /**
   * Replicate the :focus-visible behavior of CSS
   *
   * @default false
   */
  focusVisible?: boolean
}
export interface UseFocusReturn {
  /**
   * If read as true, then the element has focus. If read as false, then the element does not have focus
   * If set to true, then the element will be focused. If set to false, the element will be blurred.
   */
  focused: Ref<boolean>
}
/**
 * Track or set the focus state of a DOM element.
 *
 * @see https://vueuse.org/useFocus
 * @param target The target element for the focus and blur events.
 * @param options
 */
export declare function useFocus(
  target: MaybeElementRef,
  options?: UseFocusOptions,
): UseFocusReturn