Express 5 is Finally Here! What This Means for Your Node.js Projects

After nearly a decade of waiting, Express.js 5 has finally arrived! This major release brings crucial updates that improve security, maintainability, and modern development practices. If you’re a Node.js developer, here’s a breakdown of what’s new in Express 5 and what you need to consider before upgrading.

Key Updates in Express.js 5

1. Modernized Node.js Support

Express 5 drops support for older Node versions, now requiring Node.js 18+. This ensures better performance and security by leveraging the latest Node.js features.

2. Improved Routing & Security

• Removed Regular Expression-Based Routes → This change prevents security vulnerabilities like ReDoS (Regular Expression Denial of Service) attacks.
• Enhanced Catch-All Routes → Now, wildcard (*) routes properly capture parameters, improving routing flexibility.

3. Full Promise Support & Better Error Handling

• Express 5 now supports returned rejected Promises in middleware, eliminating the need for extra try-catch blocks.
• Previously, unhandled errors in async functions would crash the app. Now, Express automatically catches and processes them.

4. Simplified Body Parsing

• The extended option for urlencoded middleware defaults to false, simplifying setup.
• Express 5 updates how body parsers work, making form and JSON data handling more efficient.

Upgrading from Express 4 to Express 5

If you’re migrating from Express 4, follow these steps:

1. Install Express 5 npm install express@next (Express 5 is still tagged as next, so you must install it manually.)
2. Update Middleware & Routing
   • Remove deprecated extended: true from urlencoded.
   • Adjust wildcard routes if necessary.
3. Refactor Error Handling
   • Remove manual try-catch blocks in middleware.
   • Ensure async functions properly handle errors.
4. Check the Official Migration Guide
   • The Express team provides documentation on potential breaking changes and best practices.

Final Thoughts

Express 5 is a long-awaited upgrade that modernizes the framework, making it more secure, efficient, and easier to maintain. While it’s currently tagged as next, a stable latest release will be available soon. If you’re not ready to upgrade yet, you can wait for long-term support (LTS) before making the switch.