Updating & upgrading
14 answers. Keep Joomla up to date, move to the next version, and fix updates that fail.
- How do I upgrade from Joomla 5 to Joomla 6?
Update to the latest Joomla 5.4 and PHP 8.3, make a backup, and turn off the old Backward Compatibility plugin. Then set the update channel to "Joomla Next" and run the update – on a test copy of your site first.
Joomla 5–6 - The update fails with "File checksum failed"
The download was damaged. Click Check for updates and try again; if it fails again, download the update package from joomla.org and use Upload & Update.
Fix - Should I turn off the Backward Compatibility plugin?
Only after everything works without it. It keeps older extensions running; turn it off on a copy of your site first and test.
CompatibilityJoomla 5–6 - How do I update Joomla?
Back up first, then open System → Update → Joomla and click Update. Patch updates (like 6.2.1 → 6.2.2) take a minute and keep your content and settings.
- How do I upgrade from Joomla 4 to Joomla 5?
Update to the latest Joomla 4.4, run the Pre-Update Check, update your extensions, then update to Joomla 5.
Joomla 4–5 - Can I go straight from Joomla 4 to Joomla 6?
No. Go one major version at a time: Joomla 4.4 → 5.4 → 6. Each step only takes a few minutes once your extensions are ready.
Compatibility - An extension isn't ready for the new version
Update it, ask its developer, or replace it. If you don't use it, uninstall it before you upgrade.
Compatibility - The update shows "AJAX loading error"
The server blocked or cut off the update. Use Upload & Update with the package from joomla.org, and ask your host about ModSecurity or time limits.
Fix - What does the Pre-Update Check tell me?
Whether your PHP settings and each installed extension are ready for the next version. Green means ready; fix or replace anything that isn't.
- The update stops at "Extracting files"
Raise max_execution_time to 300 and memory_limit to 256M in your PHP settings, then run the update again.
Fix - Joomla doesn't offer the newest version
Click Check for updates in System → Update. If nothing shows, check the update channel in Options and that "Joomla! Core" is enabled in System → Update Sites.
Fix - Can I undo an update?
Not with a button. Restore the backup you made before updating; that is why you always back up first.
- Can Joomla update itself automatically?
Yes, from Joomla 5.4: System → Update → Joomla → Options → Automated Updates. New sites have it on; sites updated from older versions turn it on there. It updates Joomla itself, not extensions.
Joomla 5–6 - How do I test an update without risking my live site?
Make a copy: back up with Akeeba Backup, restore it on a staging subdomain with Kickstart, and update the copy first.