GUIDE
Joomla 6 upgrade checklist
Most failed CMS upgrades fail for the same few reasons: no backup, the wrong PHP version, or an extension that has not caught up. Work through this list on a copy of your site first.
Updated 6 October 2026
joomla6.com is independent and unofficial. For release notes, downloads and the supported upgrade path, use the official Joomla 6 page. Check version numbers there before you act on anything here.
1. Take a backup you have tested
A backup you have never restored is a guess. Take a full copy of the site files and the database, then restore it somewhere else and open the site. Keep the copy until the upgraded site has run cleanly for a few weeks.
- Files: everything in the Joomla folder, including
configuration.php, images and any custom templates. - Database: a full export of every table, not only the ones with the Joomla prefix if you have custom tables.
- Your host's snapshot is useful, but also keep a copy you control.
2. Check your PHP version
Joomla 6 needs PHP 8.3 or later, according to the project. Find your current version in the administrator under System, then System Information, on the PHP tab. If it is older, plan the PHP change as its own step. Our hosting guide explains how to ask your host or change it yourself.
Moving PHP and moving Joomla at the same time makes problems hard to trace. Change one, test, then change the other.
3. List every extension and template
Open the Extensions manager and write down each third-party component, module, plugin and template, with its version. For each one, check the developer's site for a statement that it works with Joomla 6.
| Status | What to do |
|---|---|
| Developer confirms Joomla 6 support | Update it to that version before the core update. |
| No statement yet | Ask the developer. Do not assume it works. |
| Abandoned or no longer needed | Disable it and plan a replacement, or remove it. |
Remove extensions you no longer use before you upgrade. Each one is a possible failure point and a security risk.
4. Use the pre-update check
Joomla's own updater includes a pre-update check that compares your server and extensions to the target version. Run it and read every warning. A red item should block the upgrade until you have fixed it. An orange item deserves a note on your list.
5. Rehearse on a staging copy
- Restore your backup to a staging site on the same kind of hosting as the live one.
- Switch the staging site to the PHP version you will use in production.
- Run the update there, then click through the pages that earn money or take enquiries: forms, shop, login, search.
- Check the administrator too, including saving an article and uploading an image.
- Write down every step you took, so the live upgrade is a repeat and not an experiment.
6. Choose a quiet time for the live update
Pick a window when traffic is low and you can stay for an hour afterward. Put the site into offline mode in Global Configuration, take one last backup, and run the update using the steps you wrote on staging.
7. Test, then watch
- Load the home page, a few inner pages, search and every form.
- Check the PHP error log for new warnings and notices.
- Re-check your sitemap, redirects and any caching or CDN rules.
- Look at your analytics and search console data for a few days. A sudden drop in pages crawled or visits points to a break you missed.
8. Know your way back
Decide before you start what a failed upgrade looks like and who decides to roll back. Rolling back means restoring both the files and the database from the backup you took in step 6. Restoring only one leaves a mismatch that causes new errors.
Common surprises
- A template that depends on removed features. Custom templates often need small changes. Test the front end carefully.
- Hand-edited core files. Changes made directly in core files vanish when the core updates. Move them into a template override or a plugin.
- Old PHP on a cheap host. Some shared plans offer limited PHP versions. If yours cannot reach the required version, that is the time to move host.