Drupal 12.0.0-alpha1 Opens Contributed Project Compatibility Testing

Core release managers published Drupal core 12.0.0-alpha1 on 2 September 2026, giving module and theme maintainers the first tagged Drupal 12 release for compatibility testing. The release is intended to expose problems caused by significant dependency and platform changes before Drupal 12 reaches beta. Drupal warns that alpha releases are not for production use and says no upgrade path will be provided between Drupal 12 alpha releases or from alpha1 to beta1.

The core release schedule sets 11 September 2026 as the deadline for Drupal 12 beta requirements, with beta1 scheduled for the week of 14 September 2026 and Drupal 12.0.0 for the week of 7 December 2026. Maintainers therefore have a short period to test contributed modules, themes and distributions against the tagged alpha before the beta dependency set is established. Another compatibility pass may still be required because the alpha release notes say further backend and frontend dependency changes can land before beta1.

The published drupal/core package requires php >=8.5.0, while Drupal 12 moves core dependencies to Symfony 8.1 and Guzzle 8. The alpha requirements issue records core testing with MariaDB 10.11 and PostgreSQL 18. Drupal's current database requirements documentation also lists PostgreSQL 18 for Drupal 12, while the alpha1 release page lists PostgreSQL 19, leaving the two Drupal.org sources inconsistent as of 8 September 2026.

Drupal 12.0.0-alpha1 no longer includes the Ban, Contact, Field Layout, History, Settings Tray, Shortcut and Telephone modules or the Stable 9 theme. Those extensions have moved to contributed projects, so sites depending on them need to account for the contributed versions during Drupal 12 upgrade preparation. Migrate Drupal and Migrate Drupal UI have also been removed without moving to contributed projects, although the Migrate API remains in core.

Drupal 12 removes database updates added before Drupal 11.4.0, so sites on Drupal 11.3.x or earlier must first update to Drupal 11.4.0 or later. The release notes recommend moving to the most recent Drupal 11 release and updating contributed projects before attempting the major-version upgrade. Drupal 12 testing also moves further toward the recommended Composer project structure: alpha installation instructions use drupal/recommended-project for new projects and drupal/core-recommended for core updates, while core tarball packaging has switched to the recommended structure as work continues to remove drupal/legacy-project as a Drupal 12 starting point.

Alpha1 does not represent the final Drupal 12 dependency target. HTMX remains on version 2 in the tagged release, while the release notes say version 4 will be included for beta1 following its stable release on 28 August 2026. Most other breaking changes have already been committed, according to the release notes, making alpha1 a useful compatibility baseline while leaving maintainers with another testing point when the beta dependency set lands.