heroku-24

Overview

Heroku-24 is the current default stack for new Heroku applications, based on Ubuntu 24.04 LTS.

Support Timeline

• General Availability: June 2024
• Default Stack: December 2024
• End of Life: April 2029

Key Features

Base Image Optimizations

• Reduced base image size by removing less frequently used packages (Bazaar, Mercurial)
• Build tools (GCC, Make, Git, system Python) available only at build time, not at runtime
• More efficient resource utilization

Multi-Architecture Support

• Published images support both amd64 and arm64 architectures
• Default Linux user changed from root to heroku

Build and Runtime Changes

• Git available only at build time (not at runtime)
• Limited locale support: C, C.utf8, POSIX, and en_US.utf8 only
• APT sources list uses new deb822 format at /etc/apt/sources.list.d/ubuntu.sources
• Reduced timezone data (only geographical regions and city names)

Fir Apps

• Only heroku/builder:24 is supported for Fir apps
• Heroku-24 is the exclusive base image for new Fir applications

Upgrading to Heroku-24

Applications should be upgraded to Heroku-24 to benefit from the latest security updates, performance improvements, and extended support timeline.

References

• Heroku-24 Stack Documentation
• Heroku-24 General Availability Announcement
• Heroku-24 Default Stack Announcement