Shared Options

Unless noted, the options in this section are applied to all dev, build, and preview.

root

Type: string
Default: process.cwd()

Project root directory (where index.html is located). Can be an absolute path, or a path relative to the current working directory.

See Project Root for more details.

base

Type: string
Default: /
Related: server.origin

Base public path when served in development or production. Valid values include:

Absolute URL pathname, e.g. /foo/
Full URL, e.g. https://bar.com/foo/ (The origin part won't be used in development so the value is the same as /foo/)
Empty string or ./ (for embedded deployment)

See Public Base Path for more details.

mode

Type: string
Default: 'development' for serve, 'production' for build

Specifying this in config will override the default mode for both serve and build. This value can also be overridden via the command line --mode option.

See Env Variables and Modes for more details.

define

Type: Record<string, any>

Define global constant replacements. Entries will be defined as globals during dev and statically replaced during build.

Vite uses esbuild defines to perform replacements, so value expressions must be a string that contains a JSON-serializable value (null, boolean, number, string, array, or object) or a single identifier. For non-string values, Vite will automatically convert it to a string with JSON.stringify.

Example:

export default defineConfig({
  define: {
    __APP_VERSION__: JSON.stringify('v1.0.0'),
    __API_URL__: 'window.__backend_api_url',
  },
})

NOTE

For TypeScript users, make sure to add the type declarations in the env.d.ts or vite-env.d.ts file to get type checks and Intellisense.

Example:

// vite-env.d.ts
declare const __APP_VERSION__: string

plugins

Type: (Plugin | Plugin[] | Promise<Plugin | Plugin[]>)[]

Array of plugins to use. Falsy plugins are ignored and arrays of plugins are flattened. If a promise is returned, it would be resolved before running. See Plugin API for more details on Vite plugins.

publicDir

Type: string | false
Default: "public"

Directory to serve as plain static assets. Files in this directory are served at / during dev and copied to the root of outDir during build, and are always served or copied as-is without transform. The value can be either an absolute file system path or a path relative to project root.

Defining publicDir as false disables this feature.

See The public Directory for more details.

cacheDir

Type: string
Default: "node_modules/.vite"

Directory to save cache files. Files in this directory are pre-bundled deps or some other cache files generated by vite, which can improve the performance. You can use --force flag or manually delete the directory to regenerate the cache files. The value can be either an absolute file system path or a path relative to project root. Default to .vite when no package.json is detected.

resolve.alias

Type:Record<string, string> | Array<{ find: string | RegExp, replacement: string, customResolver?: ResolverFunction | ResolverObject }>

Will be passed to @rollup/plugin-alias as its entries option. Can either be an object, or an array of { find, replacement, customResolver } pairs.

When aliasing to file system paths, always use absolute paths. Relative alias values will be used as-is and will not be resolved into file system paths.

More advanced custom resolution can be achieved through plugins.

Using with SSR

If you have configured aliases for SSR externalized dependencies, you may want to alias the actual node_modules packages. Both Yarn and pnpm support aliasing via the npm: prefix.

resolve.dedupe

Type: string[]

If you have duplicated copies of the same dependency in your app (likely due to hoisting or linked packages in monorepos), use this option to force Vite to always resolve listed dependencies to the same copy (from project root).

SSR + ESM

For SSR builds, deduplication does not work for ESM build outputs configured from build.rollupOptions.output. A workaround is to use CJS build outputs until ESM has better plugin support for module loading.

resolve.conditions

Type: string[]
Default: ['module', 'browser', 'development|production'] (defaultClientConditions)

Additional allowed conditions when resolving Conditional Exports from a package.

A package with conditional exports may have the following exports field in its package.json:

json

{
  "exports": {
    ".": {
      "import": "./index.mjs",
      "require": "./index.js"
    }
  }
}

Here, import and require are "conditions". Conditions can be nested and should be specified from most specific to least specific.

development|production is a special value that is replaced with production or development depending on the value of process.env.NODE_ENV. It is replaced with production when process.env.NODE_ENV === 'production' and development otherwise.

Note that import, require, default conditions are always applied if the requirements are met.

Resolving subpath exports

Export keys ending with "/" is deprecated by Node and may not work well. Please contact the package author to use * subpath patterns instead.

resolve.mainFields

Type: string[]
Default: ['browser', 'module', 'jsnext:main', 'jsnext'] (defaultClientMainFields)

List of fields in package.json to try when resolving a package's entry point. Note this takes lower precedence than conditional exports resolved from the exports field: if an entry point is successfully resolved from exports, the main field will be ignored.

resolve.extensions

Type: string[]
Default: ['.mjs', '.js', '.mts', '.ts', '.jsx', '.tsx', '.json']

List of file extensions to try for imports that omit extensions. Note it is NOT recommended to omit extensions for custom import types (e.g. .vue) since it can interfere with IDE and type support.

resolve.preserveSymlinks

Type: boolean
Default: false

Enabling this setting causes vite to determine file identity by the original file path (i.e. the path without following symlinks) instead of the real file path (i.e. the path after following symlinks).

Related: esbuild#preserve-symlinks, webpack#resolve.symlinks

html.cspNonce

Type: string
Related: Content Security Policy (CSP)

A nonce value placeholder that will be used when generating script / style tags. Setting this value will also generate a meta tag with nonce value.

css.modules

Type:

interface CSSModulesOptions {
  getJSON?: (
    cssFileName: string,
    json: Record<string, string>,
    outputFileName: string,
  ) => void
  scopeBehaviour?: 'global' | 'local'
  globalModulePaths?: RegExp[]
  exportGlobals?: boolean
  generateScopedName?:
    | string
    | ((name: string, filename: string, css: string) => string)
  hashPrefix?: string
  /**
   * default: undefined
   */
  localsConvention?:
    | 'camelCase'
    | 'camelCaseOnly'
    | 'dashes'
    | 'dashesOnly'
    | ((
        originalClassName: string,
        generatedClassName: string,
        inputFile: string,
      ) => string)
}

Configure CSS modules behavior. The options are passed on to postcss-modules.

This option doesn't have any effect when using Lightning CSS. If enabled, css.lightningcss.cssModules should be used instead.

css.postcss

Type: string | (postcss.ProcessOptions & { plugins?: postcss.AcceptedPlugin[] })

Inline PostCSS config or a custom directory to search PostCSS config from (default is project root).

For inline PostCSS config, it expects the same format as postcss.config.js. But for plugins property, only array format can be used.

The search is done using postcss-load-config and only the supported config file names are loaded. Config files outside the workspace root (or the project root if no workspace is found) are not searched by default. You can specify a custom path outside of the root to load the specific config file instead if needed.

Note if an inline config is provided, Vite will not search for other PostCSS config sources.

css.preprocessorOptions

Type: Record<string, object>

Specify options to pass to CSS pre-processors. The file extensions are used as keys for the options. The supported options for each preprocessor can be found in their respective documentation:

sass/scss:
- Select the sass API to use with api: "modern-compiler" | "modern" | "legacy" (default "modern-compiler" if sass-embedded is installed, otherwise "modern"). For the best performance, it's recommended to use api: "modern-compiler" with the sass-embedded package. The "legacy" API is deprecated and will be removed in Vite 7.
- Options (modern)
- Options (legacy).
less: Options.
styl/stylus: Only define is supported, which can be passed as an object.

Example:

export default defineConfig({
  css: {
    preprocessorOptions: {
      less: {
        math: 'parens-division',
      },
      styl: {
        define: {
          $specialColor: new stylus.nodes.RGBA(51, 197, 255, 1),
        },
      },
      scss: {
        api: 'modern-compiler', // or "modern", "legacy"
        importers: [
          // ...
        ],
      },
    },
  },
})

css.preprocessorOptions[extension].additionalData

Type: string | ((source: string, filename: string) => (string | { content: string; map?: SourceMap }))

This option can be used to inject extra code for each style content. Note that if you include actual styles and not just variables, those styles will be duplicated in the final bundle.

Example:

export default defineConfig({
  css: {
    preprocessorOptions: {
      scss: {
        additionalData: `$injectedColor: orange;`,
      },
    },
  },
})

css.preprocessorMaxWorkers

Experimental: Give Feedback
Type: number | true
Default: 0 (does not create any workers and run in the main thread)

If this option is set, CSS preprocessors will run in workers when possible. true means the number of CPUs minus 1.

css.devSourcemap

Experimental: Give Feedback
Type: boolean
Default: false

Whether to enable sourcemaps during dev.

css.transformer

Experimental: Give Feedback
Type: 'postcss' | 'lightningcss'
Default: 'postcss'

Selects the engine used for CSS processing. Check out Lightning CSS for more information.

Duplicate @imports

Note that postcss (postcss-import) has a different behavior with duplicated @import from browsers. See postcss/postcss-import#462.

css.lightningcss

Experimental: Give Feedback
Type:

import type {
  CSSModulesConfig,
  Drafts,
  Features,
  NonStandard,
  PseudoClasses,
  Targets,
} from 'lightningcss'

{
  targets?: Targets
  include?: Features
  exclude?: Features
  drafts?: Drafts
  nonStandard?: NonStandard
  pseudoClasses?: PseudoClasses
  unusedSymbols?: string[]
  cssModules?: CSSModulesConfig,
  // ...
}

Configures Lightning CSS. Full transform options can be found in the Lightning CSS repo.

json.namedExports

Type: boolean
Default: true

Whether to support named imports from .json files.

json.stringify

Type: boolean | 'auto'
Default: 'auto'

If set to true, imported JSON will be transformed into export default JSON.parse("...") which is significantly more performant than Object literals, especially when the JSON file is large.

If set to 'auto', the data will be stringified only if the data is bigger than 10kB.

esbuild

Type: ESBuildOptions | false

ESBuildOptions extends esbuild's own transform options. The most common use case is customizing JSX:

export default defineConfig({
  esbuild: {
    jsxFactory: 'h',
    jsxFragment: 'Fragment',
  },
})

By default, esbuild is applied to ts, jsx and tsx files. You can customize this with esbuild.include and esbuild.exclude, which can be a regex, a picomatch pattern, or an array of either.

In addition, you can also use esbuild.jsxInject to automatically inject JSX helper imports for every file transformed by esbuild:

export default defineConfig({
  esbuild: {
    jsxInject: `import React from 'react'`,
  },
})

When build.minify is true, all minify optimizations are applied by default. To disable certain aspects of it, set any of esbuild.minifyIdentifiers, esbuild.minifySyntax, or esbuild.minifyWhitespace options to false. Note the esbuild.minify option can't be used to override build.minify.

Set to false to disable esbuild transforms.

assetsInclude

Type: string | RegExp | (string | RegExp)[]
Related: Static Asset Handling

Specify additional picomatch patterns to be treated as static assets so that:

They will be excluded from the plugin transform pipeline when referenced from HTML or directly requested over fetch or XHR.
Importing them from JS will return their resolved URL string (this can be overwritten if you have a enforce: 'pre' plugin to handle the asset type differently).

The built-in asset type list can be found here.

Example:

export default defineConfig({
  assetsInclude: ['**/*.gltf'],
})

logLevel

Type: 'info' | 'warn' | 'error' | 'silent'

Adjust console output verbosity. Default is 'info'.

customLogger

Type:

interface Logger {
  info(msg: string, options?: LogOptions): void
  warn(msg: string, options?: LogOptions): void
  warnOnce(msg: string, options?: LogOptions): void
  error(msg: string, options?: LogErrorOptions): void
  clearScreen(type: LogType): void
  hasErrorLogged(error: Error | RollupError): boolean
  hasWarned: boolean
}

Use a custom logger to log messages. You can use Vite's createLogger API to get the default logger and customize it to, for example, change the message or filter out certain warnings.

import { createLogger
, defineConfig
 } from 'vite'

const logger
 = createLogger
()
const loggerWarn
 = logger
.warn


logger
.warn
 = (msg
, options
) => {
  // Ignore empty CSS files warning
  if (msg
.includes
('vite:css') && msg
.includes
(' is empty')) return
  loggerWarn
(msg
, options
)
}

export default defineConfig
({
  customLogger
: logger
,
})

clearScreen

Type: boolean
Default: true

Set to false to prevent Vite from clearing the terminal screen when logging certain messages. Via command line, use --clearScreen false.

envDir

Type: string
Default: root

The directory from which .env files are loaded. Can be an absolute path, or a path relative to the project root.

See here for more about environment files.

envPrefix

Type: string | string[]
Default: VITE_

Env variables starting with envPrefix will be exposed to your client source code via import.meta.env.

SECURITY NOTES

envPrefix should not be set as '', which will expose all your env variables and cause unexpected leaking of sensitive information. Vite will throw an error when detecting ''.

If you would like to expose an unprefixed variable, you can use define to expose it:

define: {
  'import.meta.env.ENV_VARIABLE': JSON.stringify(process.env.ENV_VARIABLE)
}

appType

Type: 'spa' | 'mpa' | 'custom'
Default: 'spa'

Whether your application is a Single Page Application (SPA), a Multi Page Application (MPA), or Custom Application (SSR and frameworks with custom HTML handling):

'spa': include HTML middlewares and use SPA fallback. Configure sirv with single: true in preview
'mpa': include HTML middlewares
'custom': don't include HTML middlewares

Learn more in Vite's SSR guide. Related: server.middlewareMode.

future

Type: Record<string, 'warn' | undefined>
Related: Breaking Changes

Enable future breaking changes to prepare for a smooth migration to the next major version of Vite. The list may be updated, added, or removed at any time as new features are developed.

See the Breaking Changes page for details of the possible options.

Shared Options ​

root ​

base ​

mode ​

define ​

plugins ​

publicDir ​

cacheDir ​

resolve.alias ​

resolve.dedupe ​

resolve.conditions ​

resolve.mainFields ​

resolve.extensions ​

resolve.preserveSymlinks ​

html.cspNonce ​

css.modules ​

css.postcss ​

css.preprocessorOptions ​

css.preprocessorOptions[extension].additionalData ​

css.preprocessorMaxWorkers ​

css.devSourcemap ​

css.transformer ​

css.lightningcss ​

json.namedExports ​

json.stringify ​

esbuild ​

assetsInclude ​

logLevel ​

customLogger ​

clearScreen ​

envDir ​

envPrefix ​

appType ​

future ​

Shared Options

root

base

mode

define

plugins

publicDir

cacheDir

resolve.alias

resolve.dedupe

resolve.conditions

resolve.mainFields

resolve.extensions

resolve.preserveSymlinks

html.cspNonce

css.modules

css.postcss

css.preprocessorOptions

css.preprocessorOptions[extension].additionalData

css.preprocessorMaxWorkers

css.devSourcemap

css.transformer

css.lightningcss

json.namedExports

json.stringify

esbuild

assetsInclude

logLevel

customLogger

clearScreen

envDir

envPrefix

appType

future