New Stack available on Scalingo: scalingo-26

What is a Stack?

Scalingo runs applications on a curated, maintained operating system image called a stack. Each stack is typically based on a widely used Linux distribution, such as Ubuntu.

Applications deployed on Scalingo target a specific stack. Buildpacks handle the process of turning an application’s source code into an executable artifact compatible with that stack.

What about scalingo-26?

At Scalingo, we aim to provide our customers with a secure, up-to-date environment so they can focus entirely on their business challenges.

Our new stack, scalingo-26, based on Ubuntu 26.04 “Resolute”, is now available on the Scalingo platform. It is not the default stack yet, but it will become the default for all new applications starting June 22, 2026. All buildpacks officially supported by Scalingo are compatible with this new stack.

Applications currently running on scalingo-24 can continue to do so. Since this stack is based on Ubuntu 24.04, Scalingo will support scalingo-24 until the end of its official support period in May 2029.

For applications currently using scalingo-24, the next section explains how to migrate them to the new stack.

How to migrate an existing application to use scalingo-26

From the dashboard, you can view and change the stack used by an application in the application’s settings, under the “General” subsection.

A guide to testing the migration to a new stack is available in the Scalingo documentation. Below is an excerpt from that page.

Create a review app containing a scalingo.json:

{
  "stack": "scalingo-26"
}

{
  "stack": "scalingo-26"
}

{
  "stack": "scalingo-26"
}

{
  "stack": "scalingo-26"
}

With this file in place, the deployed review app will use the new scalingo-26 stack. Make sure the review app deploys successfully and runs without issues. You can then switch your main application to the scalingo-26 stack with:

scalingo --app

scalingo --app

scalingo --app

scalingo --app

And redeploy your application:

git commit --allow-empty --message="Upgrading to scalingo-26"
git

git commit --allow-empty --message="Upgrading to scalingo-26"
git

git commit --allow-empty --message="Upgrading to scalingo-26"
git

git commit --allow-empty --message="Upgrading to scalingo-26"
git

Your application is now using the latest Ubuntu long-term support version! 🙌

scalingo-26: stability and security improvement for developers

At Scalingo, we are committed to providing developers with the best platform possible. The release of our new stack, scalingo-26, marks an important milestone for teams building and running applications on Scalingo.

This latest stack provides users with a curated and maintained operating system image designed to improve stability, performance, and security. It gives developers a reliable, well-supported environment they can trust to build and run their applications with confidence.