Express vs Fastify: Which Node.js Framework Should You Choose?

Fastify handles 80,000 requests per second. Express handles 25,000. That's a 3x performance gap — and it's been consistent across every major benchmark since Fastify's release.

But Express still has 76 million weekly downloads. Fastify has 5.4 million. If performance were the only thing that mattered, those numbers would be reversed.

We compared them using real npm data from PkgPulse. Here's the full picture.

At a Glance

| Metric | Express | Fastify | |--------|---------|---------| | Weekly Downloads | 76.6M | 5.4M | | Requests/sec | 20,000–30,000 | 70,000–80,000 | | First Release | 2010 | 2016 | | Current Version | 5.x | 5.x | | TypeScript | @types/express | Built-in | | Validation | Manual (middleware) | Built-in (JSON Schema) | | Logging | Manual (middleware) | Built-in (Pino) | | Async/Await | Supported (4.x+) | Default pattern |

See the full live comparison at pkgpulse.com/compare/express-vs-fastify

The headline stat: Fastify is 3-5x faster, but Express has 14x more downloads. Performance and adoption are telling different stories — and both are worth understanding.

Performance: The Numbers

Fastify's speed advantage is real, well-documented, and architectural — not the result of one clever optimization.

Synthetic benchmarks: ~80,000 req/sec (Fastify) vs ~25,000 req/sec (Express)
Real-world APIs: ~30,000+ req/sec (Fastify) vs ~10,000–15,000 (Express)
Extreme scenarios: Some benchmarks show Fastify at 114,000 req/sec — over 5.6x faster

Why the Gap Exists

Four architectural decisions compound:

find-my-way router — Radix-tree-based routing outperforms Express's path-to-regexp by roughly 3x
Schema-based serialization — JSON Schema definitions compile to optimized serialization functions at startup, avoiding runtime reflection
Pino logging — The fastest Node.js logger, using worker threads for I/O instead of blocking the event loop
Plugin system vs middleware chain — Fastify encapsulates plugins rather than walking a per-request middleware stack

When This Actually Matters

For most CRUD APIs serving fewer than 1,000 requests/second, both frameworks handle the load comfortably. The performance gap becomes significant when:

High concurrent connections — real-time apps, webhooks, IoT backends
Microservices — each service needs to be lean and fast
Latency-sensitive APIs — financial services, gaming backends, edge functions
Cloud cost optimization — faster response times mean fewer instances. At scale, that's real money.

Developer Experience

Express: Everyone Knows It

Express's API is almost universally familiar:

const express = require('express');
const app = express();

app.get('/api/users/:id', (req, res) => {
  res.json({ id: req.params.id, name: 'John' });
});

app.listen(3000);

Strengths:

Minimal onboarding friction — most Node.js developers have used Express
Truly minimal — adds almost nothing on top of Node's HTTP module
Massive middleware ecosystem: 50,000+ packages on npm
Stack Overflow has answers for every Express question you'll ever have

Weaknesses:

No built-in validation, logging, or serialization — you assemble these yourself
TypeScript via DefinitelyTyped, not first-class
Middleware chain ordering can become hard to reason about in large apps
Error handling patterns are inconsistent across the ecosystem

Fastify: Structured and Batteries-Included

Fastify provides more out of the box, at the cost of a slightly steeper initial learning curve:

const fastify = require('fastify')({ logger: true });

fastify.get('/api/users/:id', {
  schema: {
    params: { type: 'object', properties: { id: { type: 'string' } } },
    response: {
      200: {
        type: 'object',
        properties: { id: { type: 'string' }, name: { type: 'string' } }
      }
    }
  }
}, async (request, reply) => {
  return { id: request.params.id, name: 'John' };
});

fastify.listen({ port: 3000 });

More verbose — but that schema definition gives you automatic validation, serialized responses (faster JSON output), and auto-generated API docs. The upfront investment pays off.

Strengths:

Built-in validation via JSON Schema — validated and serialized automatically
First-class TypeScript with type inference from schemas
Pino logger included — structured, fast, production-ready
Plugin system with proper encapsulation (vs global middleware)
Async/await is the default, not an afterthought

Weaknesses:

Smaller ecosystem — fewer off-the-shelf plugins than Express
Plugin system and decorator pattern have a learning curve
Schema-first approach requires upfront investment
Fewer community answers (though official docs are excellent)

Ecosystem

Express

Express's ecosystem is unmatched in breadth:

Auth: Passport.js (500+ strategies)
Validation: express-validator, Joi, Zod (manual integration)
ORM: Prisma, TypeORM, Drizzle — all work seamlessly
Templating: EJS, Pug, Handlebars
Meta-frameworks: NestJS uses Express by default

Fastify

Fastify's ecosystem is smaller but growing steadily:

Auth: @fastify/auth, @fastify/jwt, @fastify/passport
Validation: Built-in (Ajv + JSON Schema)
CORS: @fastify/cors
Rate limiting: @fastify/rate-limit
API docs: @fastify/swagger — auto-generated from your schemas
Meta-frameworks: NestJS supports Fastify as an alternative adapter

One critical bridge: @fastify/express is a compatibility layer that lets you use Express middleware directly in Fastify. This dramatically lowers the migration barrier.

Migration Path

If you're considering moving from Express to Fastify, the pragmatic approach:

Start new services in Fastify — don't rewrite working Express code
Use the compatibility layer — @fastify/express mounts Express middleware in Fastify
Migrate route by route — move high-traffic endpoints first for maximum impact
Adopt schemas gradually — start with response schemas (free performance boost), add request validation later

The migration doesn't have to be all-or-nothing. Many teams run both frameworks across a microservices architecture, and that's perfectly fine.

When to Choose Express

Your team already knows it — familiarity reduces bugs and speeds development
You're prototyping or building an MVP — Express's simplicity gets you to production fastest
You need specific middleware that only exists for Express
Performance isn't a bottleneck — most apps don't need 80K req/sec
You're using NestJS — Express is the default adapter with better documentation

When to Choose Fastify

Performance matters — high-throughput APIs, real-time services, microservices at scale
You want built-in validation — JSON Schema validation with auto-generated API docs
TypeScript is a requirement — first-class types with schema inference
You're starting a new project — no Express legacy to maintain
Observability is important — Pino logging is genuinely best-in-class
You want to reduce cloud costs — 3-5x throughput means fewer server instances

The Verdict

Express is the safe, proven choice. It's the framework most Node.js developers already know, with the largest ecosystem and the most community resources. For most projects, it's perfectly adequate — and "adequate" isn't a criticism.

Fastify is the modern, performance-first choice. For new projects in 2026, it gives you better throughput, built-in validation, superior TypeScript support, and structured logging — all without sacrificing developer experience.

The trend is clear: Fastify's download growth rate is outpacing Express's, and new projects increasingly adopt it as the default. But Express isn't going anywhere — with 76M weekly downloads, it remains the backbone of the Node.js ecosystem for good reason.

Compare Express vs Fastify on PkgPulse →

Frequently Asked Questions

Is Fastify faster than Express?

Yes, significantly. Fastify handles 70,000–80,000 requests/sec compared to Express's 20,000–30,000 under similar conditions. The gap comes from Fastify's radix-tree router, schema-based serialization, and plugin architecture. See the live data on PkgPulse.

Should I switch from Express to Fastify?

Not necessarily. If Express is working for your current load, migration has costs. The pragmatic approach: start new services in Fastify and migrate high-traffic existing routes gradually using the @fastify/express compatibility layer.

What is the fastest Node.js framework?

Among mainstream frameworks, Fastify consistently tops benchmarks at 70,000–80,000 req/sec. Newer frameworks like Hono and uWebSockets.js can be faster in specific scenarios, but Fastify offers the best balance of performance, ecosystem maturity, and developer experience. Compare options at PkgPulse.

Explore more backend comparisons: Express vs Hono, Fastify vs Hono, or Express vs Koa on PkgPulse.

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