Rankings live at addresses, not in software. Keep the addresses, redirect the rest, and Google barely notices the move.
Google does not rank WordPress. It ranks pages at addresses. Your services page ranks because of the words on it, the links pointing to it, and the years it has been there.
Change the software behind that address and keep the words, and very little moves. Change the address without telling Google where it went, and the page starts from zero. Almost every ranking loss in a redesign comes from that second mistake.
Before anything else, get a complete list of your live pages. Your sitemap at yourbusiness.com/sitemap.xml is a start. Google Search Console shows which addresses actually get traffic. Combine the two.
Note which pages bring visitors and which bring calls. Those are the pages you protect first. A blog post from 2019 with no traffic can go. Your main service pages cannot.
The safest move is no move. If your plumbing page lives at /plumbing today, it should live at /plumbing tomorrow. Same slug, same content, new file underneath.
This is the quiet advantage of rebuilding from your existing site instead of starting fresh. Think Bright Sites reads your live pages and rebuilds them at the same addresses. Most of the redirect work disappears because nothing moved.
Some addresses will change. WordPress often creates ugly ones, like /?p=123 or /category/uncategorized/. Each old address needs a 301 redirect to its best new home.
One to one is the rule. Do not send twenty old pages to the homepage. Google treats that as a soft delete. Send each one to the page that replaced it. If nothing replaced it, send it to the closest topic.
Every page has a title tag and a meta description. They took years to settle. Bring them across exactly, then improve them later if you want.
Bring across your local business markup, or add it if you never had it. Keep the name, address and phone identical to your Google Business Profile. Keep your images with the same descriptive file names and alt text where you can.
Go live on your domain, then submit the new sitemap in Search Console. Over the next two to four weeks, watch the Coverage and Performance reports. A short dip is normal as Google recrawls. A dip that keeps going means a missed redirect.
Keep the old WordPress site reachable for a month, not live but available, in case you need to check what a page said. Then shut it off and stop paying for the plugins.
Print this and check it off. It is the same list we use.
Paste your URL. We rebuild it, show you the match, and measure the speed. No template. No blank page. Human review from start to finish.