WordPress 6.4 RC1: an archive of the October 2023 preview
Historical release note: WordPress published 6.4 Release Candidate 1 on 17 October 2023. The final 6.4 release followed on 7 November 2023. This page describes that preview, not a current upgrade recommendation.
What the preview introduced
Twenty Twenty-Four brought a new default theme with reusable layouts and patterns. Editor improvements included image lightboxes, custom pattern categories and filtering, writing and link controls, updated block toolbars, a redesigned Command Palette, renamable Group blocks, media previews in List View and additional design tools.
Other changes to test
The official announcement also described Block Hooks, accessibility improvements and performance work on template loading, script-loading strategies and autoloaded options. These changes affected different workflows; a feature list alone did not establish compatibility with every theme or plugin.
Testing and upgrades
At the time, RC1 could be tested with WordPress Beta Tester, a direct download or WP-CLI. Release candidates belong on a separate test site, not a live or business-critical installation. For an upgrade today, consult the current supported release information, back up files and the database, test key user journeys, and prepare a recovery procedure. Do not install an obsolete release candidate simply to follow this archived article.