webppl is a small but feature-rich probabilistic programming language embedded in Javascript.

Local install

Install webppl in two easy steps:

  1. Install nodejs
  2. Run npm install -g webppl

Now, the webppl command is globally available.

To upgrade to the latest version, run npm update -g webppl.


The primary reference for webppl is our web book, The Design and Implementation of Probabilistic Programming Languages.

To learn more about how to set up and use webppl, take a look at our documentation and the examples.

For probabilistic modeling in general, our other web book, Probabilistic Models of Cognition, might be of interest.


We encourage you to contribute to webppl! Check out our guidelines for contributors and join the webppl-dev mailing list.


Say “web people”.


The webppl code base is open source and freely available for commerical and non-commercial use under the MIT license.


If you use webppl in academic projects and papers, please cite as:

N. D. Goodman and A. Stuhlm├╝ller (electronic). The Design and Implementation of Probabilistic Programming Languages. Retrieved from http://dippl.org. [bibtex]

  title = {{The Design and Implementation of Probabilistic Programming Languages}},
  author = {Goodman, Noah D and Stuhlm\"{u}ller, Andreas},
  year = {2014},
  howpublished = {\url{http://dippl.org}},
  note = {Accessed: }


The webppl project is supported by grants from DARPA, under agreement number FA8750-14-2-0009, and the Office of Naval Research, grant number N00014-13-1-0788.