#cli #load-testing #performance #http

app oha

Ohayou(おはよう), HTTP load generator, inspired by rakyll/hey with tui animation

34 releases

Uses new Rust 2021

0.5.3 Jul 16, 2022
0.5.1 Mar 29, 2022
0.4.7 Oct 15, 2021
0.4.6 Jul 5, 2021
0.2.1 Mar 29, 2020

#7 in Profiling

Download history 52/week @ 2022-04-22 221/week @ 2022-04-29 408/week @ 2022-05-06 617/week @ 2022-05-13 132/week @ 2022-05-20 223/week @ 2022-05-27 321/week @ 2022-06-03 27/week @ 2022-06-10 33/week @ 2022-06-17 71/week @ 2022-06-24 103/week @ 2022-07-01 53/week @ 2022-07-08 177/week @ 2022-07-15 116/week @ 2022-07-22 95/week @ 2022-07-29 61/week @ 2022-08-05

450 downloads per month

MIT license


oha (おはよう)

GitHub Actions Crates.io Arch Linux Homebrew Gitter

oha is a tiny program that sends some load to a web application and show realtime tui inspired by rakyll/hey.

This program is written in Rust and powered by tokio and beautiful tui by tui-rs.



This program is built on stable Rust.

cargo install oha

You can optionally build oha against rustls instead of native-tls.

cargo install --no-default-features --features rustls oha

On Arch Linux

pacman -S oha

On macOS (Homebrew)

brew install oha

On Debian (Azlux's repository)

echo "deb http://packages.azlux.fr/debian/ buster main" | sudo tee /etc/apt/sources.list.d/azlux.list
wget -qO - https://azlux.fr/repo.gpg.key | sudo apt-key add -
apt update
apt install oha


  • Linux - Tested on Ubuntu 18.04 gnome-terminal
  • Windows 10 - Tested on Windows Powershell
  • MacOS - Tested on iTerm2


-q option works different from rakyll/hey. It's set overall query per second instead of for each workers.

oha 0.5.3
hatoo <hato2000@gmail.com>
Ohayou(おはよう), HTTP load generator, inspired by rakyll/hey with tui animation.

    oha [FLAGS] [OPTIONS] <url>

    <URL>    Target URL.

    -n <N_REQUESTS>
            Number of requests to run. [default: 200]

    -c <N_WORKERS>
            Number of workers to run concurrently. You may should increase limit to number of open
            files for larger `-c`. [default: 50]

    -z <DURATION>
            Duration of application to send requests. If duration is specified, n is ignored.
            Examples: -z 10s -z 3m.

            Rate limit for all, in queries per second (QPS)

            Correct latency to avoid coordinated omission problem. It's ignored if -q is not set.

            No realtime tui

        --fps <FPS>
            Frame per second for tui. [default: 16]

    -m, --method <METHOD>
            HTTP method [default: GET]

    -H <HEADERS>
            Custom HTTP header. Examples: -H "foo: bar"

    -t <TIMEOUT>
            Timeout for each request. Default to infinite.

            HTTP Accept Header.

    -d <BODY_STRING>
            HTTP request body.

    -D <BODY_PATH>
            HTTP request body from file.


    -a <BASIC_AUTH>
            Basic authentication, username:password

        --http-version <HTTP_VERSION>
            HTTP version. Available values 0.9, 1.0, 1.1, 2.

        --host <HOST>
            HTTP Host header

            Disable compression.

    -r, --redirect <REDIRECT>
            Limit for number of Redirect. Set 0 for no redirection. [default: 10]

            Disable keep-alive, prevents re-use of TCP connections between different HTTP requests.

            Lookup only ipv6.

            Lookup only ipv4.

            Accept invalid certs.

        --connect-to <CONNECT_TO>
            Override DNS resolution and default port numbers with strings like

    -h, --help
            Print help information

    -V, --version
            Print version information


Stress test in more realistic conditon

oha uses default options inherited from rakyll/hey but you may need to change options to stress test in more realistic condition.

I suggest to run oha with following options.

oha <-z or -n> -c <number of concurrent connections> -q <query per seconds> --latency-correction --disable-keepalive <target-address>
  • --disable-keepalive

    In real, user doesn't query same URL using Keep-Alive. You may want to run without Keep-Alive.

  • --latency-correction

    You can avoid Coordinated Omission Problem by using --latency-correction.


Feel free to help us!

Here are some issues to improving.

  • Write tests
  • Improve tui design.
    • Show more information?
    • There are no color in realtime tui now. I want help from someone who has some color sense.
  • Improve speed
    • I'm new to tokio. I think there are some space to optimize query scheduling.
  • Output like CSV or JSON format.
  • Improve histogram in summary output
    • It uses very simple algorithm now.


~413K SLoC