Today we are excited to announce the availability of WooCommerce 4.0. The latest release of WooCommerce has been in development since January 2020, but a lot of improvements has been in the works since 2018. WooCommerce core has had 743 commits from 21 contributors, but we should also mention a huge amount of effort from the WC Admin team and the code that now becomes a part of the core with a history of 3500 commits from 45 contributors.
4.0 is a “major” release. This means that the version is not fully backwards compatible with sites running various versions of WooCommerce 3.x. Therefore, we recommend testing the upgrade on a staging site copy before upgrading your live store and creating a backup of your code and database. Please see this guide for more details.