Heroku Generations

Last updated December 03, 2024

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
Cloud Native Buildpacks shim
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.

Feature Fir Cedar
Heroku run:inside X X
One-off dynos (heroku run:detached) X X
Private databases X X
Logs X X
Log drains X X
Encrypted Config Vars X X
Github integration (auth, sync, chatops) X X
git push (Git service) X X
Custom Buildpacks X X
Automated Certificate Management (Heroku ACM) X X
Heroku Routing X X
Usage tracking and dashboard display X X
Add-on support X X
Pipelines (incl. promotions) X X
Review Apps X X
Release Phase X X
HTTP/2 to the Router X X
Dyno autoscaling To Be Added X
Heroku Run (CLI Command and Dashboard Console) To Be Added X
Heroku CI To Be Added X
Heroku ACM Wildcard Domains To Be Added X
Network Error Logging To Be Added X
Trusted IP Ranges To Be Added X
Internal Routing To Be Added X
VPC Peering To Be Added X
VPN support To Be Added X
Private Spaces DNS Service Discovery. To Be Added X
Heroku Metrics (log stream, eventbus, language, autoscaling) To Be Added X
x86 architecture support To Be Added X
Shield Compliance To Be Added X
Router maintenance & error pages To Be Added X
Availability monitoring To Be Added X

Cedar-Only Features

Some features from Cedar-generation Private Spaces have been or will be replaced by improved Fir-only features.

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.

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.

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