httprouter — Lightweight High-Performance HTTP Router for Go

Introduction

httprouter is a minimal Go HTTP router focused purely on speed and correctness. It uses a compressed radix tree (trie) for route matching, which means lookups are independent of the number of registered routes. The library is a popular foundation for higher-level frameworks like Gin.

What httprouter Does

• Matches HTTP routes using a compressed radix tree with zero allocations on the hot path
• Supports named parameters (:name) and catch-all parameters (*filepath)
• Implements the standard http.Handler interface for net/http compatibility
• Detects conflicting routes at registration time to prevent ambiguity
• Provides automatic OPTIONS and 405 Method Not Allowed responses

Architecture Overview

The router stores each HTTP method's routes in a separate radix tree. When a request arrives, it walks the tree character-by-character, resolving named and wildcard segments along the way. Because the tree is compressed, common prefixes share a single node, keeping memory usage low. Parameters are extracted into a slice that is stack-allocated in most cases, avoiding heap allocation entirely.

Self-Hosting & Configuration

• Install with go get github.com/julienschmidt/httprouter (Go 1.18+)
• Register routes with router.GET, router.POST, etc. for each HTTP method
• Set router.NotFound to a custom handler for 404 responses
• Set router.PanicHandler to recover from panics inside handlers gracefully
• Enable trailing-slash redirects with router.RedirectTrailingSlash = true

Key Features

• Only router in Go with truly zero heap allocation per request
• Named and catch-all path parameters with no regex overhead
• Conflict detection at startup prevents silent route shadowing
• Fully compatible with net/http middleware via http.Handler
• Battle-tested as the routing engine inside the Gin framework

Comparison with Similar Tools

• Gorilla Mux — regex-based matching, more flexible but slower lookup
• Chi — radix tree like httprouter, but adds middleware chaining and context support
• Gin — full framework built on httprouter with middleware, logging, and JSON helpers
• net/http DefaultServeMux — simple prefix matching, no parameters or method routing

FAQ

Q: Why choose httprouter over Gin? A: httprouter is just a router. If you want only routing without framework overhead, it is the lighter choice. Gin adds middleware, binding, and rendering on top.

Q: Does httprouter support middleware? A: Not directly. You can wrap handlers manually or use a library like Alice to chain http.Handler middleware.

Q: Can httprouter handle regex routes? A: No. It supports named parameters and catch-alls only. For regex-based routing, consider Gorilla Mux.

Q: Is httprouter still maintained? A: Yes. Development is stable with occasional updates, and its API is considered complete.

Sources

• https://github.com/julienschmidt/httprouter
• https://pkg.go.dev/github.com/julienschmidt/httprouter