Let’s say you have been tasked to upgrade an older version of WordPress. WordPress team has been doing a great job keeping versions compatible and the upgrades succeed in 99.99% of the time which is awesome and is probably taking them lots of time and effort to do this.
Backups
Before you do anything. It’s super important to take a backup. Actually we recommend 3 backups using 3 different ways.
And make sure you download them on your computer!
One can be done using Duplicator plugin
Another one All-in-One WP Migration plugin
the third one can be a done from the control panel but make sure you backup the database and the files
Test Upgrade on a Staging WordPress Site
The next step is to do a test upgrade on a Staging WordPress site so you can see any potential errors.
Then update each plugin one by one and check the logs.
Next, update the theme
Finally Update WordPress