Skip to content
Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time


License: MIT Python 3.7

nmtpytorch allows training of various end-to-end neural architectures including but not limited to neural machine translation, image captioning and automatic speech recognition systems. The initial codebase was in Theano and was inspired from the famous dl4mt-tutorial codebase.

nmtpytorch received valuable contributions from the Grounded Sequence-to-sequence Transduction Team of Frederick Jelinek Memorial Summer Workshop 2018:

Loic Barrault, Ozan Caglayan, Amanda Duarte, Desmond Elliott, Spandana Gella, Nils Holzenberger, Chirag Lala, Jasmine (Sun Jae) Lee, Jindřich Libovický, Pranava Madhyastha, Florian Metze, Karl Mulligan, Alissa Ostapenko, Shruti Palaskar, Ramon Sanabria, Lucia Specia and Josiah Wang.

If you use nmtpytorch, you may want to cite the following paper:

  author    = {Ozan Caglayan and
               Mercedes Garc\'{i}a-Mart\'{i}nez and
               Adrien Bardet and
               Walid Aransa and
               Fethi Bougares and
               Lo\"{i}c Barrault},
  title     = {NMTPY: A Flexible Toolkit for Advanced Neural Machine Translation Systems},
  journal   = {Prague Bull. Math. Linguistics},
  volume    = {109},
  pages     = {15--28},
  year      = {2017},
  url       = {},
  doi       = {10.1515/pralin-2017-0035},
  timestamp = {Tue, 12 Sep 2017 10:01:08 +0100}


You may want to install NVIDIA's Apex extensions. As of February 2020, we only monkey-patched nn.LayerNorm with Apex' one if the library is installed and found.


You can install nmtpytorch from PyPI using pip (or pip3 depending on your operating system and environment):

$ pip install nmtpytorch


We provide an environment.yml file in the repository that you can use to create a ready-to-use anaconda environment for nmtpytorch:

$ conda update --all
$ git clone
$ conda env create -f nmtpytorch/environment.yml

IMPORTANT: After installing nmtpytorch, you need to run nmtpy-install-extra to download METEOR related files into your ${HOME}/.nmtpy folder. This step is only required once.

Development Mode

For continuous development and testing, it is sufficient to run python develop in the root folder of your GIT checkout. From now on, all modifications to the source tree are directly taken into account without requiring reinstallation.


We currently only provide some preliminary documentation in our wiki.

Release Notes