Show HN: Molab, a cloud-hosted Marimo notebook workspace

61 akshayka 8 7/18/2025, 6:40:30 PM molab.marimo.io ↗
We launched marimo [1], an open-source reactive Python notebook, last year on HackerNews. Today, the most popular recent feature request in Google Colab’s issue tracker asks for marimo support in Colab [2].

Rather than try to convince Google to replace their notebook with marimo, we decided to just build our own cloud-hosted notebook service instead. We're calling this molab (mo for marimo), and we're launching it today.

You can try it at https://molab.marimo.io

Some features:

- Persistent storage

- Link sharing (notebooks are public but undiscoverable, like secret GitHub Gists)

- Download notebooks to your machine, reuse them as Python scripts or apps

- Upload local notebooks to the cloud from our CLI (coming soon)

- Real-time collaboration (coming soon)

- Configure computational resources to obtain more CPU or GPU (coming soon)

marimo is a modern notebook for modern data workflows; we also built molab on a modern tech stack:

- Notebook dependencies are managed by uv, enabling lighting-fast package installation (thanks to uv’s cache and more generally its performant implementation). uv makes it easy to run molab notebooks locally, too: uvx marimo edit <notebook-url> brings the notebook down to your machine.

- Persistent storage is powered by R2, Cloudflare’s zero-egress object store.

- We use Pydantic logfire to monitor our deployment.

- While our implementation is agnostic to the compute backend (stay tuned!), we’re currently running on Modal for fast startups (not to mention a slick developer experience). Modal sandboxes make it easy for us define containers at runtime, containing notebook code and their dependencies. (Shout out to Eric Zhang from Modal for helping us get started.)

molab is free to use, as long as usage is reasonable. Our goal is to make is as easy as possible for our community to use marimo notebooks.

Finally, learn more at our announcement blog: https://marimo.io/blog/announcing-molab

If this interests you, please give molab a shot and please share feedback — here or on Discord (https://marimo.io/discord).

P.S. This is not our commercial product, this is really just for our community.

[1] https://github.com/marimo-team/marimo [2] https://github.com/googlecolab/colabtools/issues?q=is%3Aissu...

Comments (8)

elashri · 47m ago
This sounds like a good tool that would help ease the usage of adopting marimo for some of the tasks that people usually use colab for. It can be used for teaching and tutorials to share.

I just want to ask about Privacy Policy of the cloud version because I couldn't find it.

akshayka · 35m ago
Thanks! Notebooks on molab are public (but undiscoverable, like public GitHub gists), and can be shared with links. This is described here: https://marimo.io/blog/announcing-molab.
lahuard · 48m ago
Marimo is the future of notebooks! This solves so many problems with collaboration using notebooks. Rooting for you guys!
matsonj · 1h ago
I was hopeful for Wasm to make this work better but it just didn't. really cool to see this available - i was wondering what the next step was.
cantdutchthis · 5h ago
Everyone: don't push live on a Friday. marimo: ... hold my beer
hmartin · 1h ago
Its completely failed several times in the course of an hour for me :'(
akshayka · 1h ago
Sorry! Did the notebook not connect to the runtime? Notebooks usually start quickly but there is variance, which we are working to tighten. If you have a notebook link/ID, we can look into it.
dmadisetti · 5h ago
Everyone knows prod doesn't break on the weekends