How to update from v3.4.2 (PHP7.4) to v3.x.y (PHP8.1)

after ~2 years I come back to Kirby.
I’m maintaining a project that runs on PHP 7.4, the Kirby version is 3.4.2.
Now the web provider has announced that it will change the PHP version to 8.0 or 8.1 (my choice) and discontinue 7.4.
I’ve googled a bit and searched the comprehensive Kirby sites but had no success. My questions are:

  1. Is there a full list of Kirby versions showing which Kirby version supports which PHP versions? I don’t always find this information on the Releases page in GitHub. What is the earliest or recommended Kirby version for PHP 8.1?
  2. How easy is an update from an old to a newer Kirby3 version? I remember that you just have to swap the /kirby folder. Is that true? Is there a page that explains this?
    Sorry, I’m feeling a bit lost for not following Kirby regularly. So I am very grateful for a few tips.
    Best regards

Support for PHP 8.0 was introduced in Kirby 3.5.0 and for PHP 8.1 in 3.6.1.

But note that there was a security update for 3.6 with and for 3.5 with which are therefore the versions you should update to if you don’t want to update to the latest version (Security Policy | Kirby CMS).

That depends on your project.

If you are using third-party plugins, make sure these plugins were updated to support the Kirby version you want to update to.

If you have your own plugins, you might have to update them as well.

The resources for breaking changes to keep in mind are the individual release pages for

3.5: Kirby 3.5 | Kirby CMS
3.6: Kirby 3.6 | Kirby CMS
3.7: Kirby 3.7 | Kirby CMS

Apart from that, the update process itself is simple:

  1. replace Kirby folder
  2. clear media folder
  3. clear Kirby cache
  4. clear your browser’s cache

It’s always easier to update if you do regular updates than when you have to keep track of multiple versions at once.


Thank you for your quick reply! :grinning: