Deploying to Heroku

Heroku is a popular all-in-one hosting solution.

For your Heroku application, you only need to select a virtual operating system (stack) and preinstalled software packages (buildpack). After installing Heroku’s CLI tools, you can use standard git commands to push your code to Heroku, where it will be built from source and deployed.

You can learn more at


You’ll need a Heroku account. If you don’t have one, please sign up here.

CLI Setup

Make sure that you’ve installed the Heroku CLI tools.

Homebrew Installation

brew tap heroku/brew && brew install heroku

Other Install Options

See alternative install options here.


Once you’ve installed the CLI, log in with the following command:

heroku login

…and follow the prompts.

Application Setup

Visit the Heroku dashboard to access your account, and create a new application from the dropdown in the upper right hand corner. Heroku will ask a few questions such as region and application name, just follow their prompts.

Example Project Creation

For this guide, we’re going to be hosting Swift NIO’s example HTTP server – you can apply these concepts to your own project. Let’s start by cloning NIO:

git clone

Make sure to make our newly cloned directory the working directory:

cd swift-nio

By default, Heroku deploys the main branch. Always make sure all changes are checked into this branch before pushing.

Connecting to Heroku

Connect your app with Heroku (replace with your app’s name):

heroku git:remote -a your-apps-name-here

Stack Selection

As of December 2023, Heroku’s default stack is Heroku 22:

heroku stack:set heroku-22 -a your-apps-name-here

Currently available stacks are listed here.

Buildpack Selection

Set the buildpack to teach Heroku how to deal with Swift. The Vapor Community buildpack is a good buildpack for any Swift project. It doesn’t install Vapor, and it doesn’t have any Vapor-specific setup.

heroku buildpacks:set vapor/vapor

Swift Version Selection

The buildpack we added looks for a .swift-version file in the project root directory to know which version of Swift to use.

echo "5.9" > .swift-version

This creates .swift-version with 5.9 as its contents.

When new versions of Swift are released, the buildpack needs to be updated before you can adopt the latest version.

Procfile Creation

Heroku uses a Procfile to know how to launch and run your app. This includes the executable name and any arguments necessary. You’ll see $PORT below, this allows Heroku to assign a specific port when it launches the app.

web: NIOHTTP1Server $PORT

You can use this command in terminal to set the file

echo "web: NIOHTTP1Server $PORT" > Procfile

The contents of this file may vary depending on your server framework. For Vapor apps, the default Procfile content is the follwowing:

web: Run serve --env production --hostname --port $PORT


Now that we have added the .swift-version and Procfile files, make sure these are committed on main to be included in your deployment:

git add .swift-version Procfile
git commit -am "Add Swift version file and Procfile"

Deployment to Heroku

When you’re ready to deploy, run this from the terminal:

git push heroku main

This will take significantly longer than regular git operations as Heroku will build your project incl. all dependencies from scratch, verify and deploy it.

More information can be found on here.