Stable Baselines3 (SB3) is a set of reliable implementations of reinforcement learning algorithms in PyTorch. It is the next major version of [Stable Baselines](https://github.com/hill-a/stable-baselines).
You can read a detailed presentation of Stable Baselines3 in the [v1.0 blog post](https://araffin.github.io/post/sb3/) or our [JMLR paper](https://jmlr.org/papers/volume22/20-1364/20-1364.pdf).
These algorithms will make it easier for the research community and industry to replicate, refine, and identify new ideas, and will create good baselines to build projects on top of. We expect these tools will be used as a base around which new ideas can be added, and as a tool for comparing a new approach against existing ones. We also hope that the simplicity of these tools will allow beginners to experiment with a more advanced toolset, without being buried in implementation details.
**Note: Despite its simplicity of use, Stable Baselines3 (SB3) assumes you have some knowledge about Reinforcement Learning (RL).** You should not utilize this library without some practice. To that extent, we provide good resources in the [documentation](https://stable-baselines3.readthedocs.io/en/master/guide/rl.html) to get started with RL.
**The performance of each algorithm was tested** (see *Results* section in their respective page),
you can take a look at the issues [#48](https://github.com/DLR-RM/stable-baselines3/issues/48) and [#49](https://github.com/DLR-RM/stable-baselines3/issues/49) for more details.
Since most of the features from the [original roadmap](https://github.com/DLR-RM/stable-baselines3/issues/1) have been implemented, there are no major changes planned for SB3, it is now *stable*.
If you want to contribute, you can search in the issues for the ones where [help is welcomed](https://github.com/DLR-RM/stable-baselines3/labels/help%20wanted) and the other [proposed enhancements](https://github.com/DLR-RM/stable-baselines3/labels/enhancement).
While SB3 development is now focused on bug fixes and maintenance (doc update, user experience, ...), there is more active development going on in the associated repositories:
- newer algorithms are regularly added to the [SB3 Contrib](https://github.com/Stable-Baselines-Team/stable-baselines3-contrib) repository
- faster variants are developed in the [SBX (SB3 + Jax)](https://github.com/araffin/sbx) repository
- the training framework for SB3, the RL Zoo, has an active [roadmap](https://github.com/DLR-RM/rl-baselines3-zoo/issues/299)
Stable-Baselines3 has some integration with other libraries/services like Weights & Biases for experiment tracking or Hugging Face for storing/sharing trained models. You can find out more in the [dedicated section](https://stable-baselines3.readthedocs.io/en/master/guide/integrations.html) of the documentation.
This allows SB3 to maintain a stable and compact core, while still providing the latest features, like Recurrent PPO (PPO LSTM), CrossQ, Truncated Quantile Critics (TQC), Quantile Regression DQN (QR-DQN) or PPO with invalid action masking (Maskable PPO).
[Stable Baselines Jax (SBX)](https://github.com/araffin/sbx) is a proof of concept version of Stable-Baselines3 in Jax, with recent algorithms like DroQ or CrossQ.
It provides a minimal number of features compared to SB3 but can be much faster (up to 20x times!): https://twitter.com/araffin2/status/1590714558628253698
To install stable-baselines on Windows, please look at the [documentation](https://stable-baselines3.readthedocs.io/en/master/guide/install.html#prerequisites).
Or just train a model with a one liner if [the environment is registered in Gymnasium](https://gymnasium.farama.org/tutorials/gymnasium_basics/environment_creation/#registering-envs) and if [the policy is registered](https://stable-baselines3.readthedocs.io/en/master/guide/custom_policy.html):
We try to maintain a list of projects using stable-baselines3 in the [documentation](https://stable-baselines3.readthedocs.io/en/master/misc/projects.html),
please tell us if you want your project to appear on this page ;)
**Important Note: We do not provide technical support, or consulting** and do not answer personal questions via email.
Please post your question on the [RL Discord](https://discord.com/invite/xhfNqQv), [Reddit](https://www.reddit.com/r/reinforcementlearning/), or [Stack Overflow](https://stackoverflow.com/) in that case.
The initial work to develop Stable Baselines3 was partially funded by the project *Reduced Complexity Models* from the *Helmholtz-Gemeinschaft Deutscher Forschungszentren*, and by the EU's Horizon 2020 Research and Innovation Programme under grant number 951992 ([VeriDream](https://www.veridream.eu/)).
The original version, Stable Baselines, was created in the [robotics lab U2IS](http://u2is.ensta-paristech.fr/index.php?lang=en) ([INRIA Flowers](https://flowers.inria.fr/) team) at [ENSTA ParisTech](http://www.ensta-paristech.fr/en).