Why Top Frontend Teams Ban `export default` and Prefer Named Exports

In JavaScript ES modules, export default has been popular for exporting a primary value, but many large‑scale front‑end teams (Google, Airbnb, Vant) now forbid or discourage it.

This is not just a stylistic debate; it stems from long‑term maintenance, team collaboration, and build efficiency considerations.

Naming consistency: the root of chaos

export default

allows the importer to choose any name, leading to inconsistent identifiers across a large codebase.

In a big project the same component may appear under many different names, whereas named exports enforce a single, fixed identifier.

// MyComponent.js
export default function MyComponent() {
  // ...
}

// App.js
import MyAwesomeComponent from './MyComponent.js'; // name can be arbitrary

Using named exports, the import name must match the exported name, guaranteeing that MyComponent stays MyComponent everywhere, which is crucial for team collaboration.

Better tree‑shaking support

Tree‑shaking removes dead code during bundling. Although modern bundlers can handle export default, named exports give static analysis a clear dependency graph, making dead‑code elimination more reliable.

Simplifying re‑exports

When building a component library, a “barrel” file (index.js) can re‑export sub‑modules. With named exports this is straightforward:

export * from './Button';
export * from './Card';

If the sub‑modules use export default, the re‑export becomes verbose:

export { default as Button } from './Button';
export { default as Card } from './Card';

Such verbosity defeats the purpose of a clean barrel file. Only when a file truly has a single purpose (e.g., a config file) is export default acceptable.

Choosing between default and named exports is a trade‑off: default export offers convenience but can cause naming inconsistency, refactoring difficulty, and unclear APIs in large, long‑living projects.

Embracing named exports leads to a more robust, clearer, and tool‑friendly code ecosystem.