In this article, we’ll be exploring one specific error called the Uncaught referenceerror exports is not defined error and diving into its details.
As a JavaScript developer, it’s completely normal to encounter errors while writing code.
These errors actually help us understand what’s wrong with our code and guide us toward finding solutions.
What is Uncaught referenceerror exports is not defined?
The error message “Uncaught ReferenceError: exports is not defined” typically occurs in JavaScript environments, such as Node.js or CommonJS, when attempting to use the exports object to export functionality from a module.
The exports object is used in Node.js and CommonJS to define the public interface of a module.
Additionally, it allows you to expose functions, objects, or values from one module to be used in other modules.
The error message “Uncaught ReferenceError: exports is not defined” suggests that the exports object is being used in a context where it is not available.
There are a few possible reasons for this error:
- Incorrect environment
- Syntax error
- Missing module.exports
Here’s an example that could trigger the “Uncaught ReferenceError: exports is not defined” error:
// example.js
exports.sayHello = function() {
console.log('Hello!');
};
If you attempt to run this code in a web browser environment, you will encounter the error because the exports object is not available in that context.
The browser environment uses a different module system called ES modules.
How to fix Uncaught referenceerror exports is not defined
The aforementioned example above, to resolve it, you can modify the code to use ES modules syntax instead:
// example.js
export function sayHello() {
console.log('Hello!');
}
In this updated code, the export keyword is used to export the sayHello function. This syntax is compatible with modern browsers that support ES modules.
Alternatively, if you are working in a Node.js or CommonJS environment, you can modify the code to use the module.exports object instead:
// example.js
module.exports = {
sayHello: function() {
console.log('Hello!');
}
};
In this case, the module.exports object is used to export the sayHello function as a property of the module.
Alternative Solutions:
If you got the error in the browser, try defining a global exports variable above the script tags that load your JS files.
<script>var exports = {};</script>
<!--📌 JS script should be below -->
<script src="index.js"></script>
This defines the exports variable and sets it to an empty object, so you won’t get an error if properties are accessed on it.
Browsers don’t support the CommonJS syntax (unless you use a tool like Webpack) of require and module.exports which cause the error.
If you run your code in the browser, try removing the module property from your tsconfig.json file and set target to es6.
{
"compilerOptions": {
"target": "es6", // 📌 set this to es6
// "module": "commonjs", //📌 REMOVE this (if browser env)
}
}
When you remove the module option and set target to es6, your ES6 modules imports and exports won’t get compiled to the older CommonJS syntax that browsers don’t support.
Modern browsers support all ES6 features, so ES6 is a good choice.
Anyway, here are other fixed errors you can refer to when you might encounter them.
Conclusion
To summarize, it can be quite frustrating to come across the error message “Uncaught ReferenceError: exports is not defined” when working with JavaScript modules.
Nevertheless, by comprehending the reasons behind it and applying the recommended solutions outlined in this article, you can effectively resolve this error and produce JavaScript code that is both modular and free from errors.
It is important to keep in mind the importance of utilizing the correct module syntax, and ensuring the correct loading order of modules to prevent any module-related problems from arising in your projects.
We hope this guide has assisted you in resolving the error effectively.
Until next time! 😊
JavaScript ReferenceError debugging checklist
- Read the error message. It usually names the exact variable that is not defined.
- Check the console for load errors. Failed script or import elsewhere often causes downstream ReferenceError.
- Verify script order. Dependencies must load first. Use
deferattribute or bundler. - Check for typos. JavaScript is case-sensitive —
userNamevsusername. - Use TypeScript. Compile-time catches every ReferenceError.
Common ReferenceError sources
- Missing import statement. Especially with modern module systems.
- Script order wrong. jQuery, React, or other libraries load after the code that uses them.
- Scope issues. let / const declared inside a block, accessed outside.
- Temporal dead zone. Access before declaration in same scope.
- Server-side vs client-side context. Browser globals not available in Node/SSR.
Modern tooling to prevent ReferenceError
- TypeScript with strict mode. All ReferenceErrors caught at compile time.
- ESLint no-undef rule. Warns on undefined identifiers.
- Vite / Webpack module bundler. Handles dependency graph automatically.
- eslint-plugin-import. Warns on unresolvable imports.
- Live testing via Playwright or Cypress. Catches runtime ReferenceErrors before deploy.
Official documentation
Frequently Asked Questions
What is JavaScript ReferenceError and what causes it?
ReferenceError is raised when JavaScript tries to use a variable that doesn’t exist in the current scope. Common causes: typo in variable name, accessing a variable declared with let/const before its declaration (temporal dead zone), assuming Node.js globals exist in the browser (or vice versa), or import path errors in ES modules.
How do I fix ‘window is not defined’ in Next.js or SSR?
Server-side rendering runs your code on the server where ‘window’ (a browser-only global) doesn’t exist. Fix: gate the code with typeof window !== ‘undefined’ OR move it into a useEffect (which only runs client-side). For Next.js, dynamic import with ssr: false also works.
How do I fix ‘fetch is not defined’ in Node.js?
fetch was browser-only until Node 18. Three fixes: (1) Upgrade to Node 18+. (2) Install node-fetch (npm install node-fetch) and import it. (3) Use axios as a cross-platform alternative. For React Native, use the built-in fetch (it’s a browser-like environment).
What is the temporal dead zone in JavaScript?
The period between when a let/const variable is hoisted to the top of its block and when it’s actually declared. Accessing it during this window throws ReferenceError. Example: console.log(x); let x = 5; throws because x hasn’t been declared yet. With var, this would print undefined instead (var is hoisted with undefined value).
Where can I find more ReferenceError fixes?
Browse the ReferenceError reference hub for 34+ specific JavaScript fixes (Node ESM, SSR, React, browser globals). For JavaScript fundamentals see the JavaScript Tutorial hub.
