go-wrk - a HTTP benchmarking tool based in spirit on the excellent wrk tool (

go get


go-wrk - an HTTP benchmarking tool

go-wrk is a modern HTTP benchmarking tool capable of generating significant load when run on a single multi-core CPU. It builds on go language go routines and scheduler for behind the scenes async IO and concurrency.

It was created mostly to examine go language ( performance and verbosity compared to C (the language wrk was written in. See -
It turns out that it is just as good in terms of throughput! And with a lot less code.

The majority of go-wrk is the product of one afternoon, and its quality is comparable to wrk.


go get  

This will download and compile go-wrk. The binary will be placed under your $GOPATH/bin directory

Command line parameters (./go-wrk -help)

Usage: go-wrk <options> <url>  
    -M      HTTP method (Default GET)  
    -T      Socket/request timeout in ms (Default 1000)  
    -c      Number of goroutines to use (concurrent connections) (Default 10)  
    -d      Duration of test in seconds (Default 10)  
    -help   Print help (Default false)  
    -no-c   Disable Compression - Prevents sending the "Accept-Encoding: gzip" header (Default false)  
    -no-ka  Disable KeepAlive - prevents re-use of TCP connections between different HTTP requests (Default false)  
    -redir  Allow Redirects (Default false)  
    -v      Print version details (Default false)  

Basic Usage

./go-wrk -c 80 -d 5

This runs a benchmark for 5 seconds, using 80 go routines (connections)


Running 10s test @  
  80 goroutine(s) running concurrently  
   142470 requests in 4.949028953s, 19.57MB read  
     Requests/sec:      28787.47  
     Transfer/sec:      3.95MB  
     Avg Req Time:      0.0347ms  
     Fastest Request:   0.0340ms  
     Slowest Request:   0.0421ms  
     Number of Errors:  0  

Benchmarking Tips

The machine running go-wrk must have a sufficient number of ephemeral ports available and closed sockets should be recycled quickly. To handle the initial connection burst the server's listen(2) backlog should be greater than the number of concurrent connections being tested.


golang is awesome. I did not need anything but this to create go-wrk.
I fully credit the wrk project ( for the inspiration and even parts of this text.
I also used similar command line arguments format and output format.