As Magento 2.3 is out, its Beta version is available for installation. Installing the current Magento version to 2.3* is quite simple through CLI. Magento in its doc provides the script to upgrade Magento to 2.3 but it doesn’t work out of the box as of now. You may also streamline your upgrade process by utilizing professional Magento 2 Upgrade Services .
Visit - https://webkul.com/blog/upgrade-magento-2-to-version-2-3/
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