ExpressJS vs Fastify: What are the differences?

Key Differences between ExpressJS and Fastify

ExpressJS and Fastify are both popular web application frameworks used for building server-side applications in Node.js. However, there are several key differences between these two frameworks.

1. Performance: Fastify is known for its exceptional performance and low overhead due to its streamlined architecture and optimized code. It can handle a significantly higher number of requests per second compared to ExpressJS, making it a preferred choice for high-performance applications.

2. Routing and Middleware: While both frameworks support routing and middleware, Fastify provides a more advanced and concise routing system. Fastify uses a tree-based routing system that offers better performance and increased flexibility in handling routes. ExpressJS, on the other hand, uses a simpler route matching mechanism.

3. Plugin System: Fastify has a robust and extensible plugin system that allows developers to easily add functionalities to their applications. This modular approach enables better code organization and promotes reusability. ExpressJS, although it has support for middleware, doesn't have a dedicated plugin system like Fastify.

4. Error Handling: Fastify provides a built-in error handling mechanism that allows developers to handle and propagate errors in a more structured way. It provides a unified error handling interface, making it easier to manage errors throughout the application. In ExpressJS, error handling is more manual and less structured.

5. Request and Response Validation: Fastify comes with built-in request validation capabilities, making it easier for developers to validate incoming data and ensure the accuracy and consistency of the request payload. ExpressJS, on the other hand, requires the use of additional middleware or external libraries for request validation.

6. Ecosystem and Community: ExpressJS has a long-standing presence in the Node.js ecosystem and a large community of developers contributing to its growth. It has a vast library of middleware and plugins available, making it easier to find solutions for common use cases. Although Fastify is gaining popularity, it currently has a smaller ecosystem and community compared to ExpressJS.

In summary, Fastify offers better performance, a more advanced routing system, a dedicated plugin system, improved error handling, built-in request validation, and a growing ecosystem. ExpressJS, on the other hand, has a larger community and a well-established presence in the Node.js ecosystem.