How to Upgrade from Joomla 5 to Joomla 6
Do not start until Joomla 5.4 is ready
Use Joomla 5.4 as the migration starting point and resolve Pre-Update Check failures before proceeding. Confirm that the site and its third-party extensions work on the target server environment, and complete a successful staging rehearsal before upgrading production.
Take a complete pre-upgrade backup
Back up the Joomla files and database immediately before the production upgrade. Preserve that backup unchanged until Joomla 6 and all critical site workflows have been verified. Do not plan on downgrading Joomla files if the upgrade fails; Joomla's documented recovery position is to restore the pre-upgrade backup.
Confirm the compatibility-plugin checks
In Joomla 5.4, disable Behaviour - Backward Compatibility and ensure Behaviour - Backward Compatibility 6 is installed and enabled. Joomla's major-version Pre-Update Check treats these as required conditions for Live Update to Joomla 6. If disabling the Joomla 5 plugin breaks the site, stop and resolve the incompatible code while still on Joomla 5.4.
Review the target and extension readiness
Open System → Update → Joomla, confirm the offered Joomla 6 target, and review every required setting and extension compatibility result. Verify uncertain third-party extensions against their vendor documentation. Do not proceed merely because an extension has no warning.
Run the Joomla update
Use Joomla's normal Administrator update workflow to start the core update. Keep the browser session available and do not intentionally interrupt extraction, database updates, or finalization. If the update reports an error, preserve the exact message and logs before attempting recovery.
Verify the Joomla 6 installation
After the update completes, sign back into Administrator and confirm the installed Joomla version. Open System → Maintenance → Database and investigate any reported schema problem. Clear relevant caches and review the PHP and web-server logs for new errors.
Test the entire site before ending the maintenance window
Test frontend pages, Administrator editing, authentication, menus, templates, forms, search, email, scheduled tasks, APIs, payments, and other business-critical extensions. Compare the result with the staging rehearsal. Keep the pre-upgrade backup until production is demonstrably stable.
Need More Help with Joomla?
Still having trouble? Open a support ticket with QuantaCade Support and we'll be happy to help where we can.
Support priority is given to QuantaCade products, services, and customers. However, we're also happy to assist fellow Joomla users with general Joomla questions and troubleshooting when possible.
QuantaCade is an independent Joomla extension developer and is not official Joomla support. Some issues involving third-party extensions, hosting environments, server configurations, or other systems outside our development control may be beyond what we're able to resolve.