Release process overview

Policy objectives

• Enable a continuous upgrade path so that site owners may update easily from one major version to the next.
• Ensure site owners know when to expect new releases and what changes they will contain.
• Allow sites a sufficiently long timeframe to move from one minor or major version to the next.
• Allow contributed modules to support both the current major branch and the next major branch without significant disruption. 
• Remain on secure, supported versions of Drupal's PHP and JavaScript dependencies.

Release types and schedules

Drupal uses semantic versioning with a predictable release schedule.

Major versions are released every two years. They contain breaking changes allowed by the continuous upgrade path. Site owners will need to ensure that contributed projects and custom code are up to date before upgrading to a new major version.

Minor versions are released every six months. They contain bug fixes, new features, and deprecations.

Patch versions are released monthly. They only contain non-disruptive bug fixes, so site owners can safely upgrade their applications. 

Sample release schedule

This is an example. The current schedule is published on the Drupal core release schedule.

Major versions

• New major versions are released every two years, in even years.  Major releases may occur in June, August, or December.
• Each major version is supported for a minimum of 4 years, until the release of two further major versions.
• Major versions are only supported while their key dependencies' versions are supported.

Minor versions

• New minor versions are released approximately every six months, in June and December. 
• Each minor version is supported for one year, with bug and security fixes for the first six months, and security fixes only for the last six months.

Maintenance minors and the LTS phase

• When a new major version is released, a corresponding minor version with the same API is released for  the previous major version. This begins the Long-Term Support (LTS) phase.
• During the LTS phase Drupal will use an LTS version of Symfony.
• During this phase, a maintenance minor for the previous major is released every six months.
• Maintenance minors can include certain bug fixes, API additions for forward compatibility, security updates, and dependency updates.

The scope and number of these changes will be reduced over time as the major version approaches its end of life.

Off-schedule minor releases

In rare cases, an unscheduled minor version will be released. This will only happen if an important bug fix is too disruptive for a patch release but cannot wait until the next scheduled minor. The unscheduled minor version will include that change only. 

Release development and preparation

• Each major or minor version typically has development, alpha, beta, and release candidate phases.
• For minor versions: 
  • The alpha, beta, and release candidate phases last approximately two weeks each.
  • The first alpha release is about 6 weeks before the minor release date.
  • The alpha phase is omitted for maintenance minors.
• For major versions:
  • The alpha phase begins once the platform requirements and Symfony dependency version for the branch are updated in an alpha1 release.
  • The beta phase begins once all identified beta blockers are completed, and lasts for two months.
  • The RC phase lasts for one month.
• No contributed project security releases will be issued on the week a new core minor or major is released.