Oracle Linux is Free 100% binary-compatible with Red Hat Enterprise Linux, same as CentOS. Unlike RHEL, Oracle Linux is free even for commercial use. Oracle only charges if you need support.
Oracle provides a script to convert CentOS to Oracle Linux
https://github.com/oracle/centos2ol
This script support CentOS 6, CentOS 7 and CentOS 8.
Before you can run the convert script, make sure you have updated the system to the latest version with yum or dnf and take a backup in case anything goes wrong.
yum update
Download update centos2ol script
wget https://raw.githubusercontent.com/oracle/centos2ol/main/centos2ol.sh
Convert your CentOS installation to Oracle Linux with the command
bash centos2ol.sh -V
Reboot the server
reboot
