Kamal

Open-source tool from 37signals for deploying containerised apps to your own servers with zero downtime.

Open sourceSelf-hostableHosting and deployment platforms

Verified facts: 3 of 3
Alternatives ranked: 4
Approved reviews: 0
Visits sent from here: 0

About Kamal

Kamal is a command-line deployment tool created by 37signals, the company behind Basecamp and HEY, after it moved its apps off the cloud. You describe servers, the container image and accessories such as databases in a YAML file, and Kamal builds the image, pushes it to a registry and rolls it out to any number of servers over SSH, using its own kamal-proxy for zero-downtime deploys, rolling restarts and automatic HTTPS. It works with bare metal or cloud VMs from any provider. Kamal ships as the default deployment tool in new Ruby on Rails apps, but it works with any app that can run in Docker. It is free and MIT-licensed. Unlike a PaaS, there is no dashboard, build service or database management: you need basic Linux and Docker knowledge, and you are responsible for the servers. In return you get cheap, portable deployments with no platform fees.

Best for: Developers comfortable with Docker who want simple deploys to their own servers.

What works

Zero-downtime deploys to any server over SSH
Free, MIT-licensed and provider-neutral
Default deployment tool in new Rails apps

Why people leave

No dashboard or managed databases
Requires Linux and Docker knowledge
You maintain servers and backups

Top Kamal alternatives

See all 4

1
Dokku
Heroku-style git push deploys on a single server.
66.5
2
Coolify
Self-hosted PaaS with a dashboard if you want more than a CLI.
62.6
3
Heroku
Fully managed platform when you would rather not touch servers.
59.6
4
Render
Managed container hosting with similar Docker-based deploys.
57.2

Why people left Kamal

In reviewers' own words, from reviews of the apps they moved to. These are their opinions, not ours.

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Kamal: common questions

Is Kamal free?

Yes. Kamal is free, open-source software that you can host yourself.

Is Kamal open source?

Yes. The source code is on GitHub at basecamp/kamal. You can also run it on your own server.

What platforms does Kamal run on?

Kamal is available for Self-hosted, Linux and macOS.

What are the best alternatives to Kamal?

The highest-ranked Kamal alternatives right now are Dokku, Coolify and Heroku. See the full ranked list for pricing, platforms and verified facts.

See all 4 Kamal alternatives

Kamal facts

3 of 3 verified

License: MIT; Checked Oct 25, 2026github.com(opens source in a new tab); “License: MIT (MIT License).”
Deploys: Zero-downtime, rolling restarts; Checked Oct 25, 2026kamal-deploy.org(opens source in a new tab); “Kamal offers zero-downtime deploys, rolling restarts”
Frameworks: Built for Rails, works with any containerised app; Checked Oct 25, 2026kamal-deploy.org(opens source in a new tab); “Originally built for Rails apps, Kamal will work with any type of web app that can be containerized.”