Fix "Module 'vite' Has No Exported Member 'defineConfig'" Error

Running into the error Module 'vite' has no exported member 'defineConfig' while working with Vite is both confusing and frustrating. This issue typically arises during the configuration stage when using TypeScript or when integrating plugins. Even though the Vite documentation clearly showcases defineConfig, TypeScript throws a module error, breaking the build and halting development. The problem looks like a simple mismatch, but resolving it requires careful inspection of environment versions, package resolution, and module types.

Root of the Problem

The error message implies that TypeScript cannot find the defineConfig export from the vite module:

Module '"vite"' has no exported member 'defineConfig'.

This is not a Vite runtime error; it’s a TypeScript-level typing issue. It usually means one of the following is happening:

You’re using an outdated version of the vite package that doesn’t yet export defineConfig.
The vite type definitions are missing or mismatched.
There’s an issue with your TypeScript compiler settings, particularly module resolution.

This issue is common when bootstrapping a Vite project manually or upgrading from an older setup.

Check Installed Version

The defineConfig helper was introduced in Vite v2.0. If you’re working on a legacy codebase or the project was initialized without explicitly updating dependencies, an older version might be installed.

Check the currently installed version:

npm list vite

Or for global installs:

npm list -g vite

If the version is below 2.x, you’ll need to upgrade:

npm install vite@latest --save-dev

The latest version ensures all typing definitions align with the current API. This also avoids issues when using modern plugin setups like vite-plugin-pages or vite-plugin-react.

Ensure Type Definitions

Even with the correct version of Vite installed, your IDE or TypeScript compiler may still struggle with types if the definitions are not properly resolved. In most setups, type definitions are bundled with the package, so there is no need to install @types/vite.

However, a mismatched or corrupted node_modules directory can break the resolution. Try clearing and reinstalling all packages:

rm -rf node_modules
rm package-lock.json
npm install

After reinstalling, ensure TypeScript detects the correct types:

Open the file with defineConfig.
Hover over defineConfig.
It should resolve to a function from vite.

Confirm Correct Import Style

Even though Vite supports both ESM and CommonJS, mixing them in vite.config.ts can confuse the compiler. If you’re working with TypeScript, make sure you’re using ES module syntax.

Correct usage:

// vite.config.ts
import { defineConfig } from 'vite'

export default defineConfig({
  // your config here
})

Incorrect usage often involves either importing from the wrong module or using CommonJS-style exports.

Validate `tsconfig.json`

A broken tsconfig.json file can silently cause TypeScript to misinterpret module resolution paths. Focus on these options in your config:

{
  "compilerOptions": {
    "module": "ESNext",
    "moduleResolution": "Node",
    "target": "ESNext",
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "types": ["vite/client"]
  },
  "include": ["src", "vite.config.ts"]
}

Not including vite.config.ts in the include array can sometimes prevent proper resolution for module types. Also, avoid overriding the typeRoots unless you’re sure about what you’re doing.

Consider Package Manager Bugs

In some scenarios, especially when switching between different package managers like npm, pnpm, and yarn, node_modules can end up in a partially resolved state. If the issue persists after reinstalling with npm, try switching to another package manager like pnpm:

pnpm install

This often resolves lingering dependency mismatches caused by hoisting issues or sub-dependency version mismatches.

Double Check File Extension

Vite supports both vite.config.js and vite.config.ts. If you’re using TypeScript but saved the file as .js, TypeScript will not process the file, and you might assume a typing issue when it’s simply being ignored.

Ensure the configuration file is named properly:

✅ vite.config.ts
❌ vite.config.js when using TypeScript
❌ vite.ts.config

Also ensure your tsconfig.json includes .ts files in the root if you’re using a monorepo or non-standard structure.

Reference Setup Example

Here’s a working setup for a basic React + Vite project with proper defineConfig resolution:

// package.json dependencies
{
  "devDependencies": {
    "vite": "^5.0.0",
    "typescript": "^5.0.0",
    "@vitejs/plugin-react": "^4.0.0"
  }
}

// vite.config.ts
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [react()],
})

This config ensures compatibility with modern plugins, React Fast Refresh, and file-based routing integrations.

Conclusion

The 'defineConfig' error usually indicates either a misalignment between Vite and TypeScript versions or a misconfigured environment. Instead of patching around it with custom type declarations, it’s better to ensure your tooling is modern, correctly structured, and aligned with community practices. When building scalable apps or experimenting with plugin support like file-based routing or protected routes, starting with a solid configuration foundation can save significant debugging time down the line.