Side-by-side NPM package comparison
Version 5.7.4
Fast and low overhead web framework, for Node.js
Version 3.1.2
Koa web app framework
Choosing between Fastify and Koa? 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.
Koa leads with 6.4M weekly downloads — roughly 1.2x more. Fastify has 5.4M weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.
Koa has the smallest gzipped bundle at 19.0 KB. Fastify comes in at 120.6 KB. A smaller bundle size means faster page loads, which improves user experience and Core Web Vitals scores.
Fastify has an overall health score of 85/100 (very good), with strong maintenance, security, popularity scores. Koa 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 Fastify if you value large community support, actively maintained, strong security track record. Choose Koa if you value large community support, actively maintained, strong security track record.
Both Fastify and Koa are solid choices for JavaScript development. Fastify 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.