Heroku Generations
Last updated December 17, 2024
Table of Contents
A generation refers to a specific version or iteration of the Heroku platform’s underlying infrastructure and tools used to run applications. Each generation represents a significant upgrade or evolution in Heroku’s technology stack, offering improved performance, security, and features. As of 2024, both the Common Runtime and Private Spaces run on the Cedar generation of the platform. Starting in 2025, Heroku is upgrading to the next generation of the platform: Fir.
Fir is currently a pilot service that is subject to the Beta Services Terms at Agreements - Salesforce.com or a written Unified Pilot Agreement if executed by Customer, and applicable terms in the Product Terms Directory. Use of this pilot or beta service is at the Customer’s sole discretion.
Cedar
The Legacy Platform
Heroku’s Cedar generation was a significant leap forward in platform capabilities. It introduced a streamlined HTTP stack, enabling advanced HTTP features and paving the way for a more flexible and powerful platform.
Key Features of Cedar
Polyglot support: Beyond the official set of Heroku languages, Cedar has a rich library of custom buildpacks contributed by partners or community developers.
Heroku run: The ability to execute arbitrary one-off dynos, providing flexibility for various tasks.
Procfile and process model: A robust mechanism for managing diverse application processes. Cedar was a cornerstone of Heroku’s platform for many years, offering a reliable, performant, and feature-rich environment for developers.
Fir
The Future of Heroku
Heroku’s latest generation, Fir, builds upon the strengths of Cedar while introducing a new era of developer experience, performance, and flexibility. Fir leverages modern cloud-native technologies to provide a seamless and efficient platform.
Key Features of Fir
Streamlined deployments: Deploy your applications effortlessly with a single command, utilizing Cloud Native Buildpacks to automate the containerization process.
Simplified and diversified dyno options: Scale your applications with ease using intuitive controls and intelligent defaults, powered by Kubernetes.
Integrated observability: Gain deep insights into your application’s performance with OpenTelemetry, seamlessly integrated into Fir and Heroku Metrics. Fir offers a powerful and predictable platform that empowers developers to build modern, cloud-native applications while maintaining the familiar Heroku developer experience.
Here are some of the key benefits of using Fir compared to the Cedar version of Private Spaces:
- Cloud native, open-source standards: Future-proof your apps with scalable solutions built on Kubernetes, OCI containers, and OpenTelemetry. Easily integrate with modern cloud ecosystems.
- Operational excellence: Powered by AWS services like EKS, Graviton, and Global Accelerator, delivering scale, resilience, and performance to keep your business running smoothly.
- Access to new features: The most modern product and feature development is happening on Fir. Start building on the new generation now to have first access to new features and platform improvements.
Fir New Feature Development Roadmap
The following new features are available or are coming to Fir. These features are not available in the Cedar generation.
| Available | Coming |
|---|---|
| Kubernetes-based | GPU dynos |
| Graviton / ARM64 dynos | OpenTelemetry log egress add-on support |
| IPv6 support | OpenTelemetry log ingress add-on support |
| Cloud Native Buildpack builds | HTTP/2 to the dyno |
| In-Space builds | HTTP/3 to the edge |
| More than 500 dynos per space | HTTP/3 to the dyno |
| Native OpenTelemetry (traces, metrics, logs) | Software Bill-of-Materials |
| OpenTelemetry drains | Dyno health check support |
| Base image updates with CNB rebase | Scale-to-zero dynos in Private Spaces |
| Enhanced Heroku networking firewalls | |
| Blue/green deployments | |
Feature Parity
We’ll update this table as we add features to Fir. You can also subscribe to our changelog to stay informed.
Cedar-Only Features
Some features from Cedar-generation Private Spaces have been or will be replaced by improved Fir-only features.
- IPv4-only spaces
- Space CIDR configuration
- Custom DNS resolvers
- Space topology
- Docker builds
- Heroku Exec
- Heroku Buttons
- Out-of-space builds
- Internal builds
Upgrade to Fir
While Cedar remains a reliable choice, Heroku recommends migrating to Fir for new applications and actively developed projects. Fir offers a more modern, efficient, and feature-rich platform.
By embracing Fir, you can take advantage of the latest advancements in cloud-native technology and accelerate your development workflow.
Get Started with Fir
After gaining access to Fir, you can start exploring by trying out one of our Getting Started guides:
- Getting Started on Heroku Fir with Node.js
- Getting Started on Heroku Fir with Python
- Getting Started on Heroku Fir with Ruby
- Getting Started on Heroku Fir with Java (Gradle)
- Getting Started on Heroku Fir with Java (Maven)
- Getting Started on Heroku Fir with Scala and Play
- Getting Started on Heroku Fir with PHP
- Getting Started on Heroku Fir with .NET
- Getting Started on Heroku Fir with Go
Have Feedback?
To report any findings or bugs during the pilot program, open a ticket at https://help.heroku.com/. The ticket will get escalated to our product team for review. You’re also encouraged to leave feedback in our Public Roadmap Item to generate a public conversation where our product team can also assist.