When Moving a Site to a New Theme or CMS You Should Expect Large Organic Search Traffic Losses

While it doesn't always happen, moving a site can cause Google and other search engines to get a little dramatic and drop your pages down the rankings while they rebuild an understanding of your site. This of course often leads to overreactions or freak out reactions from marketing managers, VPs, CEOs, business owners, and other stakeholders.

You should always move your site during an off-season and give it about 60-90 days to fully recover the lost organic search traffic.

Example: Of a major theme change causing this for a medical industry website

Conversation: About traffic losses moving to Shopify on Reddit