/vite

Vite Features

Vite 8: TS/JSX transforms run on Oxc (oxc option, not esbuild), dep pre-bundling on Rolldown, and CSS minification on Lightning CSS by default. esbuild/rollupOptions still work as deprecated aliases.

Glob Import

Import multiple modules matching a pattern:

const modules = import.meta.glob('./dir/*.ts')
// { './dir/foo.ts': () => import('./dir/foo.ts'), ... }

for (const path in modules) {
  modules[path]().then((mod) => {
    console.log(path, mod)
  })
}

Eager Loading

const modules = import.meta.glob('./dir/*.ts', { eager: true })
// Modules loaded immediately, no dynamic import

Named Imports

const modules = import.meta.glob('./dir/*.ts', { import: 'setup' })
// Only imports the 'setup' export from each module

const defaults = import.meta.glob('./dir/*.ts', { import: 'default', eager: true })

Multiple Patterns

const modules = import.meta.glob(['./dir/*.ts', './another/*.ts'])

Negative Patterns

const modules = import.meta.glob(['./dir/*.ts', '!**/ignored.ts'])

Custom Queries

const svgRaw = import.meta.glob('./icons/*.svg', { query: '?raw', import: 'default' })
const svgUrls = import.meta.glob('./icons/*.svg', { query: '?url', import: 'default' })

Case-Insensitive Matching (Vite 8)

// matches Module.js, module.js, MODULE.js
const modules = import.meta.glob('./dir/module*.js', { caseSensitive: false })

Asset Import Queries

URL Import

import imgUrl from './img.png'
// Returns resolved URL: '/src/img.png' (dev) or '/assets/img.2d8efhg.png' (build)

Explicit URL

import workletUrl from './worklet.js?url'

Raw String

import shaderCode from './shader.glsl?raw'

Inline/No-Inline

import inlined from './small.png?inline'    // Force base64 inline
import notInlined from './large.png?no-inline'  // Force separate file

Web Workers

import Worker from './worker.ts?worker'
const worker = new Worker()

// Or inline:
import InlineWorker from './worker.ts?worker&inline'

Preferred pattern using constructor:

const worker = new Worker(new URL('./worker.ts', import.meta.url), {
  type: 'module',
})

Environment Variables

Built-in Constants

import.meta.env.MODE      // 'development' | 'production' | custom
import.meta.env.BASE_URL  // Base URL from config
import.meta.env.PROD      // true in production
import.meta.env.DEV       // true in development
import.meta.env.SSR       // true when running in server

Custom Variables

Only VITE_ prefixed vars exposed to client:

# .env
VITE_API_URL=https://api.example.com
DB_PASSWORD=secret  # NOT exposed to client

console.log(import.meta.env.VITE_API_URL) // works
console.log(import.meta.env.DB_PASSWORD)  // undefined

Mode-specific Files

.env                # always loaded
.env.local          # always loaded, gitignored
.env.[mode]         # only in specified mode
.env.[mode].local   # only in specified mode, gitignored

TypeScript Support

// vite-env.d.ts
interface ImportMetaEnv {
  readonly VITE_API_URL: string
}

interface ImportMeta {
  readonly env: ImportMetaEnv
}

HTML Replacement

<p>Running in %MODE%</p>
<script>window.API = "%VITE_API_URL%"</script>

CSS Modules

Any .module.css file treated as CSS module:

import styles from './component.module.css'
element.className = styles.button

With camelCase conversion:

// .my-class -> myClass (if css.modules.localsConvention configured)
import { myClass } from './component.module.css'

JSON Import

import pkg from './package.json'
import { version } from './package.json'  // Named import with tree-shaking

HMR API

if (import.meta.hot) {
  import.meta.hot.accept((newModule) => {
    // Handle update
  })
  
  import.meta.hot.dispose((data) => {
    // Cleanup before module is replaced
  })
  
  import.meta.hot.invalidate()  // Force full reload
}

WebAssembly

ESM Integration (Vite 8)

Import a .wasm file directly — Vite instantiates it and re-exposes its exports as named ESM exports. Behaves as an async module (needs top-level await):

import { add } from './add.wasm'
console.log(add(1, 2)) // 3

For TS support, enable allowArbitraryExtensions and add add.d.wasm.ts. SSR builds rely on node:fs, so this only works in Node-compatible runtimes.

Manual Initialization

import init from './example.wasm?init'
const instance = await init({ imports: { /* ... */ } })
instance.exports.test()

Chunk Import Map Optimization (Vite 8, experimental)

Set build.chunkImportMap: true to reference chunks by stable ID via an import map instead of hashed URLs. Prevents cascading cache invalidation (updating a leaf chunk no longer invalidates its importers). Requires import.meta.resolve support (use @vitejs/plugin-legacy for older browsers).