Try Mojo🔥

An introduction to the Mojo Playground, where you can try Mojo in a virtual environment.

The Mojo language is still very young, but we want your feedback!

The Mojo standard library, compiler, and runtime are not available for local development yet, so we created a hosted development environment where you can try it out. We call it the Mojo Playground!

To provide the best experience possible, the Mojo Playground currently supports a limited number of people. We plan to scale up quickly so everybody can get access over time.

Get started

  1. Sign up for access to the Mojo Playground.

  2. When you receive access, log in to the Mojo Playground using the email address you provided in the above form.

  3. Share feedback, ideas, issues, or just chat with other users in our Mojo community. Also feel free to share your Mojo code with others.

What to expect

  • The Mojo Playground is a JupyterHub environment in which everybody has access to the same Mojo standard library, but each user has a private volume in which you can write and save your own Mojo programs.
  • We’ve included a handful of notebooks to show you Mojo basics and demonstrate its capabilities. The first one, “Hello, Mojo,” is a walkthrough of all the major language features. (If you don’t have access yet, you can read the rendered notebooks here.)
  • The number of vCPU cores available in your cloud instance may vary, so baseline performance is not representative of the language. However, as you will see in the Matmul.ipynb notebook, Mojo’s relative performance over Python is significant.
  • There might be some bugs. Please report issues and feedback on GitHub.


  • Rename the included notebooks if you make any changes. These files will reset upon any server refresh or update, sorry. So if you rename the files, your changes will be safe.
  • You can use %%python at the top of a notebook cell and write normal Python code. Variables, functions, and imports defined in a Python cell are available for access in future Mojo cells.


  • Did we mention that the included notebooks will lose your changes?
    Rename the files if you want to save your changes.
  • The Mojo environment does not have network access, so you cannot install other tools or Python packages. However, we’ve included a variety of popular Python packages, such as numpy, pandas, and matplotlib (see how to import Python modules).
  • Redefining implicit variables is not supported (variables without a let or var in front). If you’d like to redefine a variable across notebook cells, please introduce the variable with either let or var.
  • You can’t use global variables inside functions - they’re only visible to other global variables.
  • For a longer list of things that don’t work yet or have pain-points, see the Mojo roadmap and sharp edges.