At the command line:

pip3 install -U minimalmodbus

or possibly:

sudo pip3 install -U minimalmodbus


Python versions 3.6 and higher are supported. This module is pure Python.

This module relies on pySerial (also pure Python) to do the heavy lifting, and it is the only dependency. It is BSD-3-Clause licensed. You can find it at the Python package index: The version of pyserial should be 3.0 or later.


Since MinimalModbus 1.0 you need to use pySerial version at least 3.0

Alternate installation on Linux

You can also manually download the compressed source files from In that case you first need to manually install pySerial from

There are compressed source files for Unix/Linux (.tar.gz) and Windows (.zip). To install a manually downloaded file use the pip tool:

python3 -m pip install filename.tar.gz

If everything else fails

You can download the raw file from GitHub, and put it in the same directory as your other code. Note that you must have pySerial installed.