Capistrano vs Kamal
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A Ruby tool that runs deployment steps on your servers over SSH from the command line.
Open source · MIT
Deploys containerized web apps to your own servers with zero-downtime switching.
The short answer
Choose Capistrano if you need…
- Developers who already deploy by logging into servers over SSH and want that process repeated reliably
- Teams deploying the same project to several stages such as staging and production
- Projects with multiple servers that need different tasks run on different roles
- Ruby or Rails teams who can use existing community Capistrano tasks
Choose Kamal if you need…
- Developers who want to self-host web apps without adopting a managed platform
- Teams running the same app across several servers over SSH
- Rails developers, since the tool was originally built for Rails
- Projects that already run in Docker containers
Side-by-side
| Capistrano | Kamal | |
|---|---|---|
| Type | Dev tool | Dev tool |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 13k | 14.7k |
| Setup difficulty | Intermediate | Intermediate |
| How you get it | Install with a package manager | See the README |
| Main language | Ruby | Ruby |
| Last code update | 4 days ago | 16 days ago |
What each one is
Capistrano
Capistrano is a framework for writing automated deployment scripts. You run the cap command, it connects to your servers over SSH, and it runs the steps needed to deploy your project. It is written in Ruby, but the README says it can deploy projects in other languages or frameworks, such as Rails, Java, or PHP.
Kamal
Kamal is a deployment tool that takes a web app packaged in Docker and puts it onto one or more servers you control, such as bare metal machines or cloud VMs. It uses a proxy called kamal-proxy to switch traffic between old and new containers so users are not interrupted during updates. It was built originally for Rails apps but the README says it works with any web app that can be containerized.
Best for
Capistrano
- Developers who already deploy by logging into servers over SSH and want that process repeated reliably
- Teams deploying the same project to several stages such as staging and production
- Projects with multiple servers that need different tasks run on different roles
- Ruby or Rails teams who can use existing community Capistrano tasks
Kamal
- Developers who want to self-host web apps without adopting a managed platform
- Teams running the same app across several servers over SSH
- Rails developers, since the tool was originally built for Rails
- Projects that already run in Docker containers
Strengths
Capistrano
- Follows a standard deployment process by default, so less setup is needed to decide structure
- Can run tasks concurrently across many servers and uses connection pooling, according to the README
- Extensible through RubyGems, with community task libraries for several frameworks
Kamal
- Supports zero-downtime deploys according to the README
- Works across multiple servers and any cloud or bare metal host
- Released under the permissive MIT license
Not ideal for
Capistrano
- People uncomfortable working on Linux servers from the command line, since the README says everything comes down to SSH commands
- Setups that cannot use key-based, passwordless SSH login, because the README says Capistrano depends on it
- Projects needing heavy sudo or interactive prompts, which the README says are difficult to do with Capistrano
- Teams wanting a tool that also provisions servers, since the README says provisioning is not done by Capistrano
Kamal
- People without Docker experience, since the README assumes containerized apps
- Those who want a hosted platform with no server management, because Kamal deploys to machines you run
- Non-web workloads, since the README describes deploying web apps specifically
Trade-offs
Capistrano
- You must write or find tasks that tell it how to start or restart your application; it does not do this on its own
- Requires key-based SSH access and a POSIX shell on the server side, and server software must be installed separately
- Needs a Ruby environment (version 2.5 or higher per the README) on the local machine
Kamal
- Requires Docker and SSH access to your servers, which adds setup work
- README is truncated here, so detailed configuration is only available on the external docs site
- Originally designed around Rails, so non-Rails apps may need more manual setup
Getting started
Capistrano
Add to Gemfile (inside a development group, with require: false)
gem "capistrano", "~> 3.17", require: falseInstall gems with Bundler
bundle installKamal
Clone the repository
git clone https://github.com/basecamp/kamalFrequently asked questions
What is the difference between Capistrano and Kamal?
Capistrano: A Ruby tool that runs deployment steps on your servers over SSH from the command line. Kamal: Deploys containerized web apps to your own servers with zero-downtime switching. Capistrano suits developers who already deploy by logging into servers over ssh and want that process repeated reliably, while Kamal suits developers who want to self-host web apps without adopting a managed platform.
Are Capistrano and Kamal free?
Capistrano: Free and open source. Kamal: Free and open source.
Is Capistrano or Kamal more popular?
Kamal has more GitHub stars (14.7k) than Capistrano (13k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Capistrano and Kamal?
Other options people compare them with include Fabric, Deployer, Dokku.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.