hey is a tiny program that sends some load to a web application.

hey was originally called boom and was influenced from Tarek Ziade's tool at tarekziade/boom. Using the same name was a mistake as it resulted in cases where binary name conflicts created confusion. To preserve the name for its original owner, we renamed this project to hey.

Installation

• Linux 64-bit: https://hey-release.s3.us-east-2.amazonaws.com/hey_linux_amd64
• Mac 64-bit: https://hey-release.s3.us-east-2.amazonaws.com/hey_darwin_amd64
• Windows 64-bit: https://hey-release.s3.us-east-2.amazonaws.com/hey_windows_amd64

Package Managers

macOS:

• Homebrew users can use brew install hey.

Usage

hey runs provided number of requests in the provided concurrency level and prints stats.

It also supports HTTP2 endpoints.

Usage: hey [options...] <url>

Options:
  -n  Number of requests to run. Default is 200.
  -c  Number of workers to run concurrently. Total number of requests cannot
      be smaller than the concurrency level. Default is 50.
  -q  Rate limit, in queries per second (QPS) per worker. Default is no rate limit.
  -z  Duration of application to send requests. When duration is reached,
      application stops and exits. If duration is specified, n is ignored.
      Examples: -z 10s -z 3m.
  -o  Output type. If none provided, a summary is printed.
      "csv" is the only supported alternative. Dumps the response
      metrics in comma-separated values format.

  -m  HTTP method, one of GET, POST, PUT, DELETE, HEAD, OPTIONS.
  -H  Custom HTTP header. You can specify as many as needed by repeating the flag.
      For example, -H "Accept: text/html" -H "Content-Type: application/xml" .
  -t  Timeout for each request in seconds. Default is 20, use 0 for infinite.
  -A  HTTP Accept header.
  -d  HTTP request body.
  -D  HTTP request body from file. For example, /home/user/file.txt or ./file.txt.
  -T  Content-type, defaults to "text/html".
  -a  Basic authentication, username:password.
  -x  HTTP Proxy address as host:port.
  -h2 Enable HTTP/2.

  -host	HTTP Host header.

  -disable-compression  Disable compression.
  -disable-keepalive    Disable keep-alive, prevents re-use of TCP
                        connections between different HTTP requests.
  -disable-redirects    Disable following of HTTP redirects
  -cpus                 Number of used cpu cores.
                        (default for current machine is 8 cores)

Previously known as github.com/rakyll/boom.

Dynamic request

You can create dynamic request with URI path or query params randomly generated on the fly. Also possible to generate dynamic request body for both -d and -D flags for method that supports body.

It supports 3 basic data types: i for integer, f for float (2 decimal point) and s for string. The dynamic URI/body is generated by interpolating placeholders (typeid:min:max) like so:

Dynamic URI

Use in the URL argument like so:

# dynamic path:
hey 'https://0.0.0.0:8080/{s}/{i}/{f}'

# dynamic query params:
hey 'https://0.0.0.0:8080/a/b/c?str={s1}&int={i1}&float={f1}'

Dynamic request body

Send in as the value of -d or a file with -D like so:

{
  "name": "{s:5:10}",  // string with 5 to 10 chars
  "age": {i:1:100},    // integer value between 1 to 100
  "score": {f:0:100},  // float value between 0 to 100
  "date": "{i1:1950:2023}-0{i2:1:9}-{i3:11:28}", // some date (yyyy-mm-dd)
}

You can mix dynamic path, params and body all in a single request as well.

Placeholder

A placeholder contains of 3 segments separated by colon: typeid:min:max.

min:max is optional with defaults min=1, max=10 so only typeid is enough.

The typeid segment contains data type (ie i, f, s) and optional integer suffix (1..N).

Multiple occurances of same typeids eg {i1:1:10}, {i1} produce same integer between 1 and 10:

[{i1:1:10}, {i1:0:0}, {i1}] => [7, 7, 7]

Different typeids eg i1, i2 etc produce different values:

[{i1:1:10}, {i2:1:10}, {i3:1:10}] => [5, 1, 9]

The placeholder rules are same for both URI and body.