What is VueUse?

VueUse is a collection of essential Vue Composition API utilities. It provides a rich set of composable functions that solve common programming challenges in Vue applications.

The Problem VueUse Solves

When building Vue applications, you often find yourself writing the same patterns over and over:

• Managing window resize listeners
• Handling mouse and keyboard events
• Storing data in localStorage
• Detecting dark mode preferences
• Working with async operations

VueUse provides battle-tested, optimized solutions to these common problems, so you can focus on building features instead of reinventing the wheel.

What Are Composables?

A composable is a function that leverages Vue's Composition API to encapsulate and reuse stateful logic. Think of it as a way to extract component logic into reusable functions.

Example: Without VueUse

Here's how you might track mouse position without VueUse:

<script setup lang="ts">
import { ref, onMounted, onUnmounted } from "vue";

const x = ref(0);
const y = ref(0);

function update(event: MouseEvent) {
  x.value = event.pageX;
  y.value = event.pageY;
}

onMounted(() => window.addEventListener("mousemove", update));
onUnmounted(() => window.removeEventListener("mousemove", update));
</script>

<template>
  <div>Mouse position: {{ x }}, {{ y }}</div>
</template>

Example: With VueUse

With VueUse's useMouse composable, the same functionality becomes much simpler:

<script setup lang="ts">
import { useMouse } from "@vueuse/core";

const { x, y } = useMouse();
</script>

<template>
  <div>Mouse position: {{ x }}, {{ y }}</div>
</template>

Notice how VueUse handles the lifecycle management, cleanup, and edge cases for you. The composable automatically adds and removes event listeners, prevents memory leaks, and works correctly even in complex scenarios.

Key Benefits

1. Reusability

Write logic once, use it anywhere. Composables can be shared across components and even projects.

2. Type Safety

VueUse is written in TypeScript and provides excellent type inference, catching errors at compile time.

3. Tree-shakable

Only the composables you use are included in your final bundle, keeping your application lean.

4. SSR Friendly

Many VueUse functions work seamlessly in server-side rendering environments like Nuxt.

5. Well-tested

Every composable is thoroughly tested and used in production by thousands of developers.

VueUse Function Categories

VueUse organizes its 200+ functions into logical categories:

• State: Reactive state management (useLocalStorage, useSessionStorage, useToggle)
• Elements: DOM element interactions (useEventListener, useIntersectionObserver)
• Browser: Browser APIs (useDark, useMediaQuery, useClipboard)
• Sensors: User input detection (useMouse, useKeyboard, useSwipe)
• Network: Network requests and connectivity (useFetch, useWebSocket)
• Animation: Timing and transitions (useInterval, useTimeout, useTransition)
• Component: Component utilities (useVModel, useTemplateRef)
• Watch: Enhanced watchers (watchDebounced, watchThrottled, until)
• Reactivity: Advanced reactivity patterns (computedAsync, refDebounced)
• Array: Reactive array operations (useArrayMap, useArrayFilter)
• Utilities: Helper functions (createSharedComposable, until, whenever)

Learning Approach in This Book

Instead of just using VueUse's functions, this book teaches you how to build them yourself. By recreating simplified versions of VueUse composables:

• You'll understand how they work internally
• You'll learn why certain patterns are used
• You'll be able to create your own custom composables for unique needs

Think of it as learning to fish instead of just receiving fish. By the end, you'll not only know how to use VueUse effectively, but also how to build composable functions that solve your specific problems.

Ready to Get Started?

Now that you understand what VueUse is and why it's valuable, let's get your environment set up and start building your first composable!