Marimo, Joute's Review

The essentials

• Reactive Python notebook: cells automatically re-execute on changes
• Free and open source
• Valid Python scripts, versionable with git
• Suited to data scientists and Python engineers suffering from Jupyter's hidden state

What is Marimo?

Marimo is a Python notebook where each cell is a pure function. When you modify a variable in a cell, all dependent cells automatically re-execute. This reactive behavior eliminates the classic Jupyter problem: hidden state that can corrupt results when cells are executed in the wrong order. A Marimo notebook is also a valid Python script, making it versionable with git and deployable as a web application.

Strengths

Guaranteed reproducibility

The reactive model prevents inconsistent states. What you see in the notebook is always consistent with the code.

Real Python script

Unlike JSON .ipynb files, a Marimo file is a standard .py. Readable git diffs, code review possible.

Deployable as a web app

A Marimo notebook can be deployed as an interactive application. Useful for sharing analyses with non-technical stakeholders.

Limitations

Learning curve

The reactive programming model is different from Jupyter. Habits need adapting, especially for loops and side effects.

Less mature ecosystem

Jupyter has years of extensions and third-party tools. Marimo is younger and the ecosystem is still being built.

Pricing

Free and open source. Check marimo.io for any cloud options.

Alternatives

For classic notebooks: Jupyter remains the reference, free. For collaborative cloud notebooks: Deepnote at 45 €/month. For no-code data analysis: Julius AI at 27 €/month.

Verdict

Marimo is a serious project that solves real Jupyter problems. If you suffer from inconsistent notebooks and want reproducibility, it's a learning time investment worth making.

FAQ

Is Marimo compatible with standard Python libraries?

Yes, pandas, numpy, matplotlib, plotly, and the full Python ecosystem are supported.

Can you migrate a Jupyter notebook to Marimo easily?

Automatic conversion exists but manual adjustments are often needed to handle the reactive model.

Does Marimo have a cloud version?

A cloud version is in development. Check marimo.io for current status.

Marimo vs Streamlit, what's the difference?

Streamlit is for creating web apps from Python scripts. Marimo is an interactive exploration environment (notebook) that can also be deployed as an app. Use cases overlap but workflows differ.

Joute may earn a commission on subscriptions taken out via links in this article. This doesn't change our reviews.