Side-by-side NPM package comparison
Version 5.2.1
Fast, unopinionated, minimalist web framework
Version 5.8.2
Fast and low overhead web framework, for Node.js
Choosing between Express and Fastify? Here's a data-driven comparison based on real npm data — downloads, bundle size, health scores, and more — to help you decide which package fits your project best.
Express leads with 83.7M weekly downloads — roughly 15.0x more. Fastify has 5.6M weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.
Express has the smallest gzipped bundle at 22.1 KB. Fastify comes in at 83.1 KB. A smaller bundle size means faster page loads, which improves user experience and Core Web Vitals scores.
Express has an overall health score of 85/100 (very good), with strong maintenance, security, popularity scores. Fastify has an overall health score of 85/100 (very good), with strong maintenance, security, popularity scores. Health scores are calculated from maintenance activity, code quality, security posture, popularity, and stability metrics.
Choose Express if you value massive community and ecosystem, actively maintained, strong security track record. Choose Fastify if you value large community support, actively maintained, strong security track record.
Both Express and Fastify are solid choices for JavaScript development. Express has the edge in overall health score (85/100), while each package brings unique strengths to the table. Evaluate them based on your project's priorities — whether that's community size, bundle efficiency, or maintenance activity — and choose the one that aligns best with your requirements.
Express and Fastify are both Node.js HTTP frameworks, but they represent different eras of server-side JavaScript. Express, created in 2010, pioneered the middleware pattern that defined Node.js web development. Its simplicity and massive middleware ecosystem make it the most widely documented Node.js framework. Fastify, launched in 2016, was built from the ground up for performance — using JSON Schema validation, efficient serialization, and an optimized plugin system to handle significantly more requests per second.
In benchmarks, Fastify consistently handles 2-3x more requests per second than Express for JSON API workloads. That gap widens under load, where Fastify's lower memory overhead and faster request parsing become critical. For most CRUD APIs, Express is fast enough — the bottleneck is usually your database, not your HTTP framework. But if you're building high-throughput microservices, real-time APIs, or handling thousands of concurrent connections, Fastify's performance advantage is meaningful and measurable.
Choose Express when you want the lowest possible learning curve, maximum middleware compatibility, and the broadest hiring pool. Choose Fastify when performance matters — API gateways, high-traffic microservices, or any service where you're paying per compute unit and want to serve more requests with fewer resources.