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ElysiaJS vs Fastify

Trust Score comparison · March 2026

ElysiaJS
74
Trust
Fair
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VS
Trust Score Δ
9
🏆 Fastify wins
Fastify
83
Trust
Good
View profile

Signal Comparison

180k / wknpm downloads3M / wk
140 commitsCommits (90d)120 commits
11k ★GitHub stars33k ★
100 q'sStack Overflow5k q's
GrowingCommunityHigh
ElysiaJSFastify

Key Differences

FactorElysiaJSFastify
LicenseMITMIT
LanguageTypeScriptTypeScript
HostedSelf-hostedSelf-hosted
Free tier
Open Source✓ Yes✓ Yes
TypeScript

Pick ElysiaJS if…

  • Building APIs on Bun where you want tRPC-style type safety with a REST interface
  • Teams already running Bun who want a native, opinionated framework
  • Microservices needing maximum throughput on Bun runtime

Pick Fastify if…

  • Performance-critical Node.js APIs where Express is a bottleneck
  • JSON-heavy APIs that benefit from schema-validated serialization
  • Teams who want Express familiarity with far better performance

Side-by-side Quick Start

ElysiaJS
import { Elysia } from 'elysia';

const app = new Elysia()
  .get('/', () => 'Hello Elysia!')
  .post('/user', ({ body }) => body, {
    body: t.Object({ name: t.String() }),
  })
  .listen(3000);
Fastify
import Fastify from 'fastify';

const app = Fastify({ logger: true });

app.get('/', async (request, reply) => {
  return { hello: 'world' };
});

await app.listen({ port: 3000 });

Community Verdict

Based on upvoted notes
🏆
Fastify wins this comparison
Trust Score 83 vs 74 · 9-point difference

Fastify leads on Trust Score with stronger signal data across downloads and community health. That said, the other tool is worth considering if your use case matches its specific strengths above.