hey

hey is a small command-line program that sends load to a web application, designed as a replacement for ApacheBench (ab). It runs a given number of requests at a given concurrency level, or for a set duration, and prints statistics on the responses.

It supports HTTP/2 endpoints as well as custom methods, headers and request bodies. hey was originally called boom and was renamed to avoid confusion with another tool of the same name.

hey is written in Go and distributed under the Apache License 2.0 on GitHub; version 0.1.5 was released in January 2026.