Typescript: Cannot use import statement outside a module

Understanding the Error

When using TypeScript or JavaScript with ES Modules (import/export syntax), you might encounter the following error:
SyntaxError: Cannot use import statement outside a module

This happens when Node.js or the TypeScript compiler does not recognize your file as an ES Module.

Solutions to Fix the Error

1. Ensure type: “module” is in package.json

For Node.js to recognize ES Module syntax, update your package.json file:

{
  "type": "module"
}

If your project uses CommonJS (require() syntax), remove “type”: “module” or use dynamic imports instead.

2. Use .mts or .mjs File Extensions

TypeScript recognizes .mts files as ES Modules. If you’re using JavaScript, rename .js to .mjs.

Example:

myfile.ts → myfile.mts

3. Configure tsconfig.json for ES Modules

Ensure your TypeScript configuration supports ES Modules by updating tsconfig.json:

{
  "compilerOptions": {
    "module": "ESNext",
    "moduleResolution": "node"
  }
}

Then, recompile your TypeScript files:
tsc

4. Use import() Instead of import Statements

If you’re dynamically importing a module, use import():

(async () => {
  const module = await import('./myModule.js');
  console.log(module.default);
})();

5. Run the Script with –loader in Node.js

If you’re running your script with Node.js, use:

node --loader ts-node/esm myfile.ts

or for JavaScript:

node --experimental-modules myfile.mjs

Final Notes

• Always check if your project setup matches the module system you’re using.
• Use CommonJS (require()) if you don’t need ES Modules.
• For modern projects, stick with ES Modules and configure your environment accordingly.

By following these steps, you can resolve the “Cannot use import statement outside a module” error in TypeScript.

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