Locust is available on PyPI and can be installed through pip or easy_install

pip install locustio


easy_install locustio

When Locust is installed, a locust command should be available in your shell (if you’re not using virtualenv—which you should—make sure your python script directory is on your path).

To see available options, run:

locust --help

Supported Python Versions

Locust supports Python 2.7, 3.3, 3.4, 3.5, and 3.6.

Installing ZeroMQ

If you intend to run Locust distributed across multiple processes/machines, we recommend you to also install pyzmq:

pip install pyzmq


easy_install pyzmq

Installing Locust on Windows

The easiest way to get Locust running on Windows is to first install pre built binary packages for gevent and greenlet and then follow the above instructions.

You can find an unofficial collection of pre built python packages for windows here:


Running Locust on Windows should work fine for developing and testing your load testing scripts. However, when running large scale tests, it’s recommended that you do that on Linux machines, since gevent’s performance under Windows is poor.

Installing Locust on OS X

The following is currently the shortest path to installing gevent on OS X using Homebrew.

  1. Install Homebrew.

  2. Install libevent (dependency for gevent):

    brew install libevent
  3. Then follow the above instructions.

Increasing Maximum Number of Open Files Limit

Every HTTP connection on a machine opens a new file (technically a file descriptor). Operating systems may set a low limit for the maximum number of files that can be open. If the limit is less than the number of simulated users in a test, failures will occur.

Increase the operating system’s default maximum number of files limit to a number higher than the number of simulated users you’ll want to run. How to do this depends on the operating system in use.