PHP 8.1 has reached End of Sale on the Pantheon platform. Newly created sites after September 30 2026 will no longer be able set their PHP version to 8.1.
Sites already running PHP 8.1 continue to run. They keep receiving LTS security coverage through PHP Runtime Generation 2, with no action required. A removal date for PHP 8.1 has not been set, and Pantheon guarantees at least 90 days of advance notice before removing any PHP version from the platform.
Action required
If you maintain a custom upstream that sets php_version: 8.1 in pantheon.upstream.yml, update it to a supported version. New sites created from that upstream may otherwise behave unexpectedly on creation.
If your site runs PHP 8.1, plan an upgrade to a recommended PHP version. Pantheon recommends PHP 8.3 or 8.4 for all production sites. For steps, see Upgrade PHP Versions.
