Before you upgrade your site, you should take an inventory of old URL's. This will establish a baseline to use as a comparison with the new site. Running this inventory will inevitably uncover URL errors such as 400/500 status codes or redirect chains, so marketers should make note of these before the migration. You will also want to Benchmark old rankings, and run analytics on any performance metrics you might have. Backing up your old site is definitely a great idea as well, and should be obligatory in case something goes wrong during the migration. Having a backup will allow you to revert to the old version of the site in the case where there's errors. Planning the Navigation and Structure of the new site is also a crucial step and a siloed structure with a hierarchy of pages is recommended.

First and foremost, you should NOT delete your old site, even when the new site is up and running. In the early stages, you should keep the old site live while redirecting to the new site. You can save a copy of the old site on a hard drive and rename it. Before using the new site live, don’t use the staging site’s robots.txt file, which could keep search engines from indexing your site. It’s always best to have a new version ready to be uploaded before the new site goes live. You also shouldn't schedule your migration when traffic levels to your website are at its highest. Doing so would interrupt user experiences, which can result in high losses of web traffic. Lastly, if your rankings do drop after the migration, don't panic, as search engines have to recrawl your site to make note of the changes.