Heroku Changelog

Build timeouts increased

2026-03-04T21:46:58Z

Build timeouts for all app builds have been increased. The build system already provides a lot of flexibility to allow occasional long-running builds when build caches are cleared and limits have been increased across the board.

Default slug size limit increased to 1GB

2026-03-04T21:46:55Z

The default slug size limit has increased from 500MB to 1GB. The slug size limit can still be increased further by opening a support ticket. App owners are encouraged to keep slugs small to ensure dynos boot quickly and reliably.

Python 3.12.13, 3.11.15 and 3.10.20 are now available

2026-03-03T20:40:03Z

Python 3.12.13, 3.11.15 and 3.10.20 are now available for use by Python apps on Heroku.

In addition, we have updated the Python 3.12, 3.11 and 3.10 major version aliases to resolve to these new Python patch versions.

We strongly recommend that you use a major version alias when specifying a Python version for your app instead of pinning to an exact patch version, so that your app receives the latest Python security updates each time you build it.

See Specifying a Python Version for details on how to configure the Python version for your app.

Heroku’s buildpacks are open source. To subscribe to Python buildpack release notifications or provide feedback, see these repositories on GitHub:

Python classic buildpack (used by Cedar-generation apps)
Python Cloud Native Buildpack (used by Fir-generation apps)

Python buildpacks updated to pip 26.0.1 and uv 0.10.7

2026-03-03T17:56:25Z

We have updated the package managers used during the build of Python apps as follows:

pip updated from 25.3 to 26.0.1 (changelog)
uv updated from 0.10.1 to 0.10.7 (changelog)

If you have not used the package manager uv before, we highly recommend giving it a try! Learn more in our blog post Heroku Adds Support for uv.

Heroku Connect now supports Salesforce API v66.0

2026-02-25T17:28:56Z

Heroku Connect now defaults to version 66.0 of the Salesforce API, the latest version available in the Spring ‘26 release. Learn how to specify the API version at connection creation on the Heroku Dev Center.

Node.js 25.7.0 and 24.14.0 now available

2026-02-25T14:51:58Z

Node.js versions 25.7.0 and 24.14.0 have been made available for builds on Heroku. For additional information, please see our article on Node.js Support.

Heroku Git and Container Registry TLS policy update

2026-02-24T16:32:38Z

Heroku Git (git.heroku.com) and the Heroku Container Registry (registry.heroku.com) now require TLS version 1.2 or later using non-CBC ciphers. Specifically, we disabled support for the ECDHE-RSA-AES128-SHA256 and ECDHE-RSA-AES256-SHA384 ciphers. This update aligns our platform services with modern security best practices and compliance standards by disabling legacy CBC ciphers. Most modern clients, including the Heroku CLI, Git, and Docker, already support these modern ciphers and don’t require any changes. This update only affects the Git and Container Registry services and doesn’t affect routing to dynos.

Heroku-22 and Heroku-24 stacks updated

2026-02-24T11:43:44Z

We updated the heroku-22 and heroku-24 stacks to pick up security fixes in upstream packages.

The format of the root filesystem on dynos has been updated from ext3 to ext4.

The new base images for each stack roll out automatically to the Common Runtime over the next 48 hours, followed by Private Spaces.

If you use Heroku’s default buildpack-powered build system/stacks, you don’t need to redeploy your app to include these changes. We automatically restart any running dynos as we roll out the new base images for each stack. For Cedar-generation apps, each time a dyno starts, the slug applies on top of the most recent base image. For Fir-generation apps, the built image gets rebased on top of the most recent base image.

If your app uses Heroku’s container stack (most don’t), you must rebuild your app’s Docker image to pick up updates in the base image specified in your Dockerfile.

See this Dev Center article for an overview of the packages available in each stack’s base image.

Changelog of packages

Stack: heroku-22

Updated cpp-11 from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3
Updated gcc-11 from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3
Updated gcc-11-base from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3
Updated libasan6 from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3
Updated libgcc-11-dev from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3
Updated libgnutls-openssl27 from version 3.7.3-4ubuntu1.7 to 3.7.3-4ubuntu1.8
Updated libgnutls30 from version 3.7.3-4ubuntu1.7 to 3.7.3-4ubuntu1.8
Updated libgnutlsxx28 from version 3.7.3-4ubuntu1.7 to 3.7.3-4ubuntu1.8
Updated libtsan0 from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3

Updates to packages available at build time only

Updated g++-11 from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3
Updated libgnutls-dane0 from version 3.7.3-4ubuntu1.7 to 3.7.3-4ubuntu1.8
Updated libgnutls28-dev from version 3.7.3-4ubuntu1.7 to 3.7.3-4ubuntu1.8
Updated libstdc++-11-dev from version 11.4.0-1ubuntu1~22.04.2 to 11.4.0-1ubuntu1~22.04.3

Stack: heroku-24

Updated gcc-14-base from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libatomic1 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libgcc-s1 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libgnutls-openssl27t64 from version 3.8.3-1.1ubuntu3.4 to 3.8.3-1.1ubuntu3.5
Updated libgnutls30t64 from version 3.8.3-1.1ubuntu3.4 to 3.8.3-1.1ubuntu3.5
Updated libgomp1 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libstdc++6 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1

Updates to packages available at build time only

Updated cpp-13 from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated cpp-13-aarch64-linux-gnu/cpp-13-x86-64-linux-gnu from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated g++-13 from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated g++-13-aarch64-linux-gnu/g++-13-x86-64-linux-gnu from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated gcc-13 from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated gcc-13-aarch64-linux-gnu/gcc-13-x86-64-linux-gnu from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated gcc-13-base from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated libasan8 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libcc1-0 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libgcc-13-dev from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated libgnutls-dane0t64 from version 3.8.3-1.1ubuntu3.4 to 3.8.3-1.1ubuntu3.5
Updated libgnutls28-dev from version 3.8.3-1.1ubuntu3.4 to 3.8.3-1.1ubuntu3.5
Updated libhwasan0 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libitm1 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated liblsan0 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libquadmath0 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libstdc++-13-dev from version 13.3.0-6ubuntu2~24.04 to 13.3.0-6ubuntu2~24.04.1
Updated libtsan2 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1
Updated libubsan1 from version 14.2.0-4ubuntu2~24.04 to 14.2.0-4ubuntu2~24.04.1

Heroku AI now supports DeepSeek V3.2, GLM 4.7, Kimi K2.5, and MiniMax M2.1 models

2026-02-18T18:07:31Z

Heroku’s Managed Inference and Agents add-on now supports these AI models:

DeepSeek V3.2: An open-weight LLM that supports conversational chat, tool-calling, and high-efficiency reasoning.
GLM 4.7: An open-weight LLM that supports conversational chat, tool-calling, and stable multi-step reasoning.
GLM 4.7 Flash: An open-weight LLM that supports conversational chat, tool-calling, and low-latency agentic tasks.
Kimi K2.5: An open-weight LLM that supports conversational chat, tool-calling, and multimodal agentic workflows.
MiniMax M2.1: An open-weight LLM that supports conversational chat, tool-calling, and long-horizon reasoning.

These models are available in the US region and support the /v1/chat/completions API endpoint. Select a model to view its documentation and get started.

Heroku AI now supports Cohere Embed V4

2026-02-18T17:22:07Z

Heroku’s Managed Inference and Agents add-on now supports Cohere’s Embed V4. Cohere Embed V4 is an advanced embedding model that can convert text into dense vector representations. The model is available in both US and EU regions, and supports the /v1/embeddings endpoint.

To learn more about using this model on Heroku, see our documentation for Cohere Embed V4.

Heroku AI now supports Claude Sonnet 4.6

2026-02-18T17:21:32Z

Heroku’s Managed Inference and Agents add-on now supports Anthropic’s Claude Sonnet 4.6. Claude Sonnet 4.6 supports conversational chat, tool calling, and enhanced reasoning for complex tasks with extended thinking. This model is optimized for enterprise apps and ideal for complex tasks like data processing, sales forecasting, and nuanced content generation.

To learn more about using this model on Heroku, see our documentation for Claude Sonnet 4.6.

PHP updates - February 2026

2026-02-18T16:25:06Z

The following new PHP runtime versions are now available:

Updates to Heroku API Compatibility Policy

2026-02-16T23:07:50Z

Summary

We are updating our API Compatibility Policy to streamline how we deliver new features and maintain the stability of the Heroku Platform APIs. These changes allow us to transition resources more efficiently from Prototype to Production, ensuring you get access to the latest platform capabilities sooner.

What’s Changing?

Updated Disruptive Change Policy for Production Resources. To ensure the Heroku Platform remains agile and can evolve alongside the broader Salesforce ecosystem, we are adjusting the notice period for disruptive changes to Production resources.

Old Policy: Disruptive changes may not occur; instead, a new major API version must be developed.
New Policy: Disruptive changes may be made to Production resources with a three-month advance notice via the Changelog.

This change allows us to improve existing endpoints without the overhead of versioning the entire API, ensuring a more cohesive experience for developers using Heroku alongside other Salesforce products.

2. Resources Maturity Lifecycle

As part of this policy change, we will be moving several resources from Prototype to Development and from Development to Production. This shift represents our commitment to the long-term stability of the tools you rely on, while giving us the flexibility to refine them as the underlying technology evolves.

Impact

Existing Integrations: No immediate action is required. Any future disruptive changes will be announced here in the Changelog in compliance with the policy.
Resource Stability: You will notice more API resources reaching “Production” status, backed by our 12-month deprecation guarantee.

Improvements to PHP app concurrency calculation when using multiple buildpacks

2026-02-16T16:56:40Z

When the Heroku PHP buildpack is used together with other official Heroku buildpacks which set a default value for the WEB_CONCURRENCY config var on dyno startup, the PHP buildpack will now use its normal method of auto-calculating the number of PHP-FPM worker processes, regardless of the order in which the buildpacks are set on the app.

This ensures automatic concurrency calculation for PHP is not affected by other official Heroku language buildpacks than ran after it during a build, and web dynos always exhibit the expected performance.

After the next deploy, existing PHP applications which also use other Heroku language buildpacks (e.g. Node.js for asset compilation) may now launch a higher number of PHP-FPM worker processes as a result of this change.

Please refer to the Optimizing PHP Application Concurrency article for full details on how concurrency for PHP apps is calculated based on dyno size and PHP memory_limit, for instructions on how to adjust or override the number of PHP-FPM worker processes, and for information on ensuring the appropriate order of buildpacks for an app.

Heroku-22 and Heroku-24 stacks updated

2026-02-16T15:10:24Z

We updated the heroku-22 and heroku-24 stacks to pick up security fixes in upstream packages. The new base images for each stack roll out automatically to the Common Runtime over the next 48 hours, followed by Private Spaces.

If your app uses Heroku’s container stack (most don’t), you must rebuild your app’s Docker image to pick up updates in the base image specified in your Dockerfile.

See this Dev Center article for an overview of the packages available in each stack’s base image.

Changelog of packages

Stack: heroku-22

Updated libexpat1 from version 2.4.7-1ubuntu0.6 to 2.4.7-1ubuntu0.7
Updated libglib2.0-0 from version 2.72.4-0ubuntu2.8 to 2.72.4-0ubuntu2.9
Updated libpng16-16 from version 1.6.37-3ubuntu0.3 to 1.6.37-3ubuntu0.4
Updated libpq5 from version 18.1-1.pgdg22.04+2 to 18.2-1.pgdg22.04+1
Updated libpython3.10-minimal from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14
Updated libpython3.10-stdlib from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14
Updated linux-libc-dev from version 5.15.0-168.178 to 5.15.0-170.180
Updated postgresql-client-17 from version 17.7-3.pgdg22.04+1 to 17.8-1.pgdg22.04+1
Updated postgresql-client-common from version 287.pgdg22.04+1 to 289.pgdg22.04+1
Updated python3.10 from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14
Updated python3.10-minimal from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14

Updates to packages available at build time only

Updated libexpat1-dev from version 2.4.7-1ubuntu0.6 to 2.4.7-1ubuntu0.7
Updated libglib2.0-bin from version 2.72.4-0ubuntu2.8 to 2.72.4-0ubuntu2.9
Updated libglib2.0-data from version 2.72.4-0ubuntu2.8 to 2.72.4-0ubuntu2.9
Updated libglib2.0-dev from version 2.72.4-0ubuntu2.8 to 2.72.4-0ubuntu2.9
Updated libglib2.0-dev-bin from version 2.72.4-0ubuntu2.8 to 2.72.4-0ubuntu2.9
Updated libpng-dev from version 1.6.37-3ubuntu0.3 to 1.6.37-3ubuntu0.4
Updated libpq-dev from version 18.1-1.pgdg22.04+2 to 18.2-1.pgdg22.04+1
Updated libpython3.10 from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14
Updated libpython3.10-dev from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14
Updated python3.10-dev from version 3.10.12-1~22.04.13 to 3.10.12-1~22.04.14

Stack: heroku-24

Updated base-files from version 13ubuntu10.3 to 13ubuntu10.4
Updated gir1.2-glib-2.0 from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libexpat1 from version 2.6.1-2ubuntu0.3 to 2.6.1-2ubuntu0.4
Updated libglib2.0-0t64 from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libpng16-16t64 from version 1.6.43-5ubuntu0.4 to 1.6.43-5ubuntu0.5
Updated libpq5 from version 18.1-1.pgdg24.04+2 to 18.2-1.pgdg24.04+1
Updated postgresql-client-17 from version 17.7-3.pgdg24.04+1 to 17.8-1.pgdg24.04+1
Updated postgresql-client-common from version 287.pgdg24.04+1 to 289.pgdg24.04+1

Updates to packages available at build time only

Updated gir1.2-glib-2.0-dev from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libexpat1-dev from version 2.6.1-2ubuntu0.3 to 2.6.1-2ubuntu0.4
Updated libgirepository-2.0-0 from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libglib2.0-bin from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libglib2.0-data from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libglib2.0-dev from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libglib2.0-dev-bin from version 2.80.0-6ubuntu3.7 to 2.80.0-6ubuntu3.8
Updated libpng-dev from version 1.6.43-5ubuntu0.4 to 1.6.43-5ubuntu0.5
Updated libpq-dev from version 18.1-1.pgdg24.04+2 to 18.2-1.pgdg24.04+1
Updated libpython3.12-minimal from version 3.12.3-1ubuntu0.10 to 3.12.3-1ubuntu0.11
Updated libpython3.12-stdlib from version 3.12.3-1ubuntu0.10 to 3.12.3-1ubuntu0.11
Updated linux-libc-dev from version 6.8.0-94.96 to 6.8.0-100.100
Updated python3.12 from version 3.12.3-1ubuntu0.10 to 3.12.3-1ubuntu0.11
Updated python3.12-minimal from version 3.12.3-1ubuntu0.10 to 3.12.3-1ubuntu0.11

New Add-on Attachment Parameter and Namespace Deprecation

2026-02-14T03:44:04Z

We are updating the Add-on Attachment resource in the Heroku Platform API. These changes provide more granular control over how add-ons are attached to apps while streamlining the API schema for future scalability.

New Parameter: namespace_config.

We have introduced a new parameter, namespace_config, to the add-on attachment resource. This parameter allows developers to define complex configuration structures for attachments, specifically aiding in scenarios where add-on resources (like Heroku Postgres credentials or Redis instances) need specific isolation levels or specialized routing within an application.

Deprecation: namespace Parameter

To simplify the API and encourage the use of the more robust namespace_config, the legacy namespace parameter is now deprecated. 30-Day Notice: The namespace parameter will remain supported until March 13, 2026. Action Required: After this date, requests using the namespace parameter will no longer be supported. We recommend all developers migrating to the namespace_config parameter immediately to avoid service interruptions.

Heroku AI now supports Claude Opus 4.6

2026-02-13T22:33:14Z

Heroku’s Managed Inference and Agents add-on now supports Anthropic’s Claude Opus 4.6. Claude Opus 4.6 provides developers with a high-intelligence LLM optimized for autonomous coding, complex reasoning, and multimodal extended thinking tasks. The model is available in both US and EU regions, and supports the Claude /v1/chat/completions schema, native image processing, and prompt caching.

To learn more about using this model on Heroku, see our documentation for Claude Opus 4.6.

GitHub Enterprise Server Integration now available

2026-02-11T19:40:28Z

GitHub Enterprise Server Integration is now available for all Enterprise accounts.

For more information, including requirements and feature activation, see the documentation on Dev Center or our blog post.

Go 1.26.0 is now available

2026-02-10T20:56:12Z

Go version 1.26.0 has been made available on Heroku.

go1.26 now defaults to go1.26.0
go1.25 is the default if no version is specified

For more information, see our page on Go Support.

.NET SDK 8.0.124, 8.0.418, 9.0.114, 9.0.311 and 10.0.103 are now available

2026-02-10T20:51:26Z

.NET SDK versions 8.0.124, 8.0.418, 9.0.114, 9.0.311 and 10.0.103 have been made available for builds on Heroku.

The .NET 8.0 SDK releases include .NET Runtime and ASP.NET Core Runtime version 8.0.24. The .NET 9.0 SDK releases include .NET Runtime and ASP.NET Core Runtime version 9.0.13. The .NET 10 SDK release include .NET Runtime and ASP.NET Core Runtime version 10.0.3.

For additional information, please see our article on .NET support.

Node.js 25.6.1 and 24.13.1 now available

2026-02-10T19:12:42Z

Node.js versions 25.6.1 and 24.13.1 have been made available for builds on Heroku. For additional information, please see our article on Node.js Support.

Python buildpacks updated to uv 0.10.1

2026-02-10T12:47:19Z

We have updated the package managers used during the build of Python apps as follows:

uv updated from 0.9.29 to 0.10.1 (changelog)

If you have not used the package manager uv before, we highly recommend giving it a try - it supports lockfiles, is extremely fast, and is actively maintained by a full-time team! Learn more in our blog post Heroku Adds Support for uv.

Added Heroku AppLink events to Enterprise Accounts audit trail

2026-02-05T18:26:16Z

Starting on February 5, 2026, the following event types are available in Audit Trails:

applink_connection.create
applink_connection.refresh
applink_connection.destroy
applink_authorization.create
applink_authorization.refresh
applink_authorization.destroy
applink_app.publish
applink_app.update
applink_app.destroy

Heroku AppLink events are now reflected in the audit trails for the associated Enterprise account using the Heroku AppLink add-on. AppLink events that occurred before February 5, 2026 aren’t reflected in these audit logs.

Go 1.24.13 and 1.25.7 now available

2026-02-04T18:22:07Z

Go versions 1.24.13 and 1.25.7 have been made available on Heroku.

go1.24 now defaults to go1.24.13
go1.25 now defaults to go1.25.7

For more information, see our page on Go Support.

Node.js 25.6.0 is now available

2026-02-04T15:36:46Z

Node.js version 25.6.0 has been made available for builds on Heroku. For additional information, please see our article on Node.js Support.