Fiber

Fiber is an Express.js inspired framework for Go, running on fasthttp (the fastest HTTP engine for Go). v3 brings generic support and better middleware.

When to Use

• Benchmarks: You need the absolute highest raw throughput.
• Node.js Background: The API (app.Get("/", ...) feels like Express).
• Zero Allocation: Obsessive memory optimization.

Core Concepts

Fasthttp

Doesn't use net/http. Much faster but incompatible with some standard library middlewares.

Prefork

Spawn multiple processes (SO_REUSEPORT) to utilize all cores.

Best Practices (2025)

Do:

• Use v3: For stable generic support.
• Be careful with Prefork: Can cause issues with socket connections if not handled.
• Use Built-in Middleware: Cache, Compress, CORS are highly optimized.

Don't:

• Don't hold references: fasthttp reuses context objects. Copy strings if you need them after handler returns.

References

• Fiber Documentation