Quick Comparison
| Express | Fastify | |
|---|---|---|
| Performance | Good | 2-3x faster |
| Ecosystem | Massive | Growing |
| TypeScript | Community types | First-class |
| Validation | External (Joi, Zod) | Built-in (JSON Schema) |
| Learning curve | Very low | Low |
When to Use Express
- Quick prototypes and MVPs
- You need a specific Express middleware
- Your team already knows Express
- Tutorials and learning (most resources use Express)
When to Use Fastify
- Performance-critical APIs
- You want built-in validation and serialization
- You prefer TypeScript-first development
- New projects where you can choose freely
Verdict
Fastify for new projects — it’s faster, has better TypeScript support, and built-in validation. Express if you need its massive middleware ecosystem or your team already knows it.