For over a decade, Express.js has been a go-to framework for building web servers in Node.js. However, one persistent pain point in Express 4 was its limited support for async/await in route handlers. If an async function threw an error or rejected a promise, it wouldn't be caught by Express's middleware chain, potentially crashing your server. Developers resorted to manual try/catch blocks, explicit next(err) calls, or third-party libraries like express-async-handler to handle this.

Enter Express 5. Released in October 2024, this major update brings native async/await support, allowing errors from async route handlers to automatically propagate to your error-handling middleware. No more wrappers, no more repetitive boilerplate – just clean, modern JavaScript.

This change aligns Express with contemporary Node.js practices (requiring Node 18+), reduces code clutter, and makes your apps more robust and maintainable.

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⭐ The Async Struggle in Express 4

To illustrate the issue, let's look at a basic async route handler in Express 4:

app.get('/user', async (req, res) => {
  const user = await getUser(); // What if this throws an error?
  res.json(user);
});