Benchmarks

These numbers measure the router alone: handlers and middleware do nothing, so what’s left is the cost of matching, params and dispatch. Your handlers will dominate a real request; the point is that the router adds as little as possible.

v5 against v4

Both versions ran on the same harness, with the same routes and requests.

net/http

Time to route one request on net/http, lower is better

• v4
• v5

Static route

20.0 ns

19.9 ns

Static, 5 segments

28.5 ns

30.2 ns

One param

87.0 ns

93.6 ns

Three params + regexp

150.1 ns

148.5 ns

Static + 3 middleware7.2× faster

170.4 ns

23.8 ns

One param + 3 middleware2.4× faster

238.4 ns

100.8 ns

404 Not Found

20.0 ns

20.3 ns

405 Method Not Allowed

60.8 ns

55.8 ns

Show as a table

Time and allocations to route one request on net/http, v4 against v5

Scenario	v4	v5
Static route	20.0 ns0 allocs	19.9 ns0 allocs
Static, 5 segments	28.5 ns0 allocs	30.2 ns0 allocs
One param	87.0 ns4 allocs	93.6 ns2 allocs
Three params + regexp	150.1 ns4 allocs	148.5 ns2 allocs
Static + 3 middleware	170.4 ns6 allocs	23.8 ns0 allocs
One param + 3 middleware	238.4 ns10 allocs	100.8 ns2 allocs
404 Not Found	20.0 ns0 allocs	20.3 ns0 allocs
405 Method Not Allowed	60.8 ns3 allocs	55.8 ns2 allocs

Apple M4 Max, Go 1.27.0, median of 5 runs.

fasthttp

Time to route one request on fasthttp, lower is better

• v4
• v5

Static route1.8× faster

30.0 ns

16.9 ns

Static, 5 segments

39.0 ns

26.2 ns

One param

50.1 ns

38.5 ns

Three params + regexp

110.2 ns

87.4 ns

Static + 3 middleware9.5× faster

173.1 ns

18.3 ns

One param + 3 middleware4.9× faster

192.8 ns

39.5 ns

404 Not Found1.9× faster

29.7 ns

15.3 ns

405 Method Not Allowed

89.0 ns

69.5 ns

Show as a table

Time and allocations to route one request on fasthttp, v4 against v5

Scenario	v4	v5
Static route	30.0 ns1 alloc	16.9 ns0 allocs
Static, 5 segments	39.0 ns1 alloc	26.2 ns0 allocs
One param	50.1 ns3 allocs	38.5 ns0 allocs
Three params + regexp	110.2 ns3 allocs	87.4 ns0 allocs
Static + 3 middleware	173.1 ns7 allocs	18.3 ns0 allocs
One param + 3 middleware	192.8 ns9 allocs	39.5 ns0 allocs
404 Not Found	29.7 ns1 alloc	15.3 ns0 allocs
405 Method Not Allowed	89.0 ns3 allocs	69.5 ns1 alloc

Apple M4 Max, Go 1.27.0, median of 5 runs.

The biggest gains are behind middleware: v4 composed each route’s middleware chain on every request, v5 composes it once at registration. On fasthttp, v5 also stopped allocating for params, 404s and literal routes.

Where net/http allocates

On net/http, a route with a few params allocates twice: that is Request.SetPathValue storing the values so r.PathValue can read them. Storing them that way also makes a one-param route a few nanoseconds slower than v4, the price of reading params with the standard r.PathValue. The matching itself allocates nothing, and neither do literal routes, middleware chains or finding no route. A 405 allocates its Allow header value, and a mount one copy of the request, as http.StripPrefix does.

v5’s own suite

Each row routes one request, except API, which averages a request across a realistic 70-route REST API.

net/http

Benchmark	Time	Memory	Allocations
Static/1One literal segment	15.0 ns	0 B	0
Static/5Five literal segments	31.6 ns	0 B	0
Static/20Twenty literal segments	98.8 ns	0 B	0
Param/1One param	90.3 ns	336 B	2
Param/5Five params	132.2 ns	336 B	2
Param/20Twenty params	883.4 ns	2137 B	7
Regexp/1One regexp param	157.6 ns	336 B	2
Regexp/5Five regexp params	434.8 ns	336 B	2
MiddlewareLiteral route behind 3 middleware	23.1 ns	0 B	0
NotFound404	18.9 ns	0 B	0
MethodNotAllowed405 with an Allow header	55.7 ns	32 B	2
MountRequest through a mounted router	83.0 ns	448 B	1
APIAverage over a 70-route API	95.5 ns	226 B	1.3

fasthttp

Benchmark	Time	Memory	Allocations
Static/1One literal segment	11.6 ns	0 B	0
Static/5Five literal segments	27.1 ns	0 B	0
Static/20Twenty literal segments	93.3 ns	0 B	0
Param/1One param	33.0 ns	0 B	0
Param/5Five params	66.6 ns	0 B	0
Param/20Twenty params	250.0 ns	0 B	0
Regexp/1One regexp param	89.7 ns	0 B	0
Regexp/5Five regexp params	353.1 ns	0 B	0
MiddlewareLiteral route behind 3 middleware	17.1 ns	0 B	0
NotFound404	14.3 ns	0 B	0
MethodNotAllowed405 with an Allow header	65.9 ns	16 B	1
MountRequest through a mounted router, URI parsing included	130.2 ns	0 B	0
APIAverage over a 70-route API	53.1 ns	0 B	0

Up to eight param values fit in a buffer on the stack; a router with a longer route takes a pooled buffer instead, so it still allocates nothing.

Run them yourself

From a clone of the repository:

go test -run '^$' -bench . -benchmem ./...

To compare two versions, run each a few times and compare with benchstat:

go test -run '^$' -bench . -count 10 ./... > new.txt
benchstat old.txt new.txt

The allocation counts are also enforced by tests: TestAllocations in each router package fails if a request allocates more than it should.