If upgrading from ProcessWire 2.5 or older, we recommend that you upgrade to ProcessWire 2.7 first. That version includes details in its README file on how to upgrade from that older version of ProcessWire. To upgrade from ProcessWire 2.6 (or newer) to ProcessWire 3.x, please follow the instructions below.
Login to the admin of your site.
/site/config.phpfile and set
$config->debug = true;to ensure you can see error messages. This is optional but recommended.
/index.phpfile with the new ones from here.
Click a navigation link in your admin, such as "Pages". You may notice a delay. This is ProcessWire compiling 3rd party modules into a format that is compatible with version 3.x. Keep an eye out for any error messages. If you see any issues, it's possible you may need to upgrade one or more 3rd party modules. If you see messages about it applying updates, keep hitting reload in your browser until you no longer see any update messages.
Once you've resolved error messages in your admin, you'll want to test out the front end of your site. Again, expect a delay while ProcessWire compiles any files to make them compatible with 3.x. Depending on your template file strategy, updates may or may not be necessary. If you run into any pages that aren't working, see the section further down on troubleshooting. Thoroughly test every aspect if your site to ensure that everything is working as you expect.
When you've confirmed a successful upgrade, remember to restore the
$config->debugsetting back to
falsein your /site/config.php file.
If you run into any trouble upgrading, please see our troubleshooting upgrades guide.