Fastify was built with one clear goal: be the fastest Node.js web framework without sacrificing developer experience. Created by Matteo Collina and Tomas Della Vedova in 2016, the framework achieves remarkable performance through careful optimization of the request/response lifecycle and JSON serialization.
Benchmarks consistently show Fastify handling significantly more requests per second than Express, often 2-3x more in JSON serialization tests. This performance comes from its use of fast-json-stringify for serialization, find-my-way for routing, and a carefully optimized plugin architecture that avoids the overhead of Express’s middleware pattern.
Fastify’s plugin system is one of its best features. Plugins are encapsulated — they get their own scope, decorators, and hooks, which prevents the namespace pollution that can happen in Express applications as they grow. The plugin architecture also makes it natural to organize code into modular, testable pieces.
The framework has built-in support for JSON Schema validation (for both request and response), which serves double duty: it validates data automatically and uses the schema to optimize JSON serialization. TypeScript support is first-class, with extensive type definitions and a developer experience that feels native.
Fastify’s ecosystem has grown substantially. Official plugins cover database integration, authentication (with @fastify/jwt and @fastify/oauth2), CORS, rate limiting, static file serving, WebSocket support, and more. The framework can also run Express middleware through a compatibility layer, easing migration.
Notable adopters include Microsoft, Belvo, and Knock. Matteo Collina, one of the creators, is a Node.js Technical Steering Committee member, which gives Fastify a close relationship with the Node.js core team.
While Express still dominates by install count, Fastify has established itself as the go-to choice for developers who care about performance and want a more modern, structured framework for their Node.js applications.
