John Mueller, Google's top SEO guy, addresses why a new website causes a temporary drop in SEO in an online talk. You can see that portion of his talk below.
However, here's our overview of why that happens:
Why a new website usually causes a drop in SEO rankings.
When a website is redesigned, the navigation most likely changes. What tha means is, the URLs on each page often change from what they were, to something different, to work within the new navigation structure. Using our site as and example, here's what we mean:
The "before" URL for the home builder section in our site used the word "portfolio" in it.
The "after" URL for the home builder section now has the word "industries" where the word "portfolio" used to be.
That means the URL changed. And when redesigning a site, it's often the case that URLs change.
So how does that relate to a drop in SEO ranking?
It's because Google, and other search engines, have indexed your previous website with all it's previous URLs. Now that your site has all (or many) new URLs, all those links (ie: URLs) Google knew about have changed. So they have to figure out the new URLs to be able to re-index your website. Indexing (or re-indexing) a website is what helps it show up in Google's search results page.
Be proactive in having Google find your new website.
The process of re-indexing your new website can be greatly expedited by submitting a site map to Google. Doing that, essentially is telling them what the new website's URLs are, letting them know where to find them. That way, you don't have to wait for their algorithms to find your new site, with its new URLs.
If your web design company isn't submitting a site map to Google and other search engines, they're not the web designers you want redesigning your site. Make sure you ask them if they'll do that before hiring them.
Be proactive in making it easy for your clients or customers.
Now consider your audience:
- If people have bookmarked any pages of your old website (with it's old URLs) in their browser,
- If those old URLs are in blog posts, or
- If those old URLs are in social media posts...
...when your customer clicks on the old links, they won't work. They'll get a "Page not found" page, as in this example. So your web design company should also create a custom "Page Not Found" page for your new website. See our "Page Not Found" page here.
Other examples of good "Page Not Found" or "Error Pages":
- Examples of good "Page Not Found" pages
- Examples of animated "Error Pages"
- And our all-time favorite Error Page here (btw, there's more information below the video):
Avoid having your customers going to a "Page Not Found" page.
If your web design company is any good, they'll do what's called a 301 redirect. This essentially redirects folks who put in an old URL, to the same page on your new website that has the new URL. It all happens behind the scenes, so it's seamless for your customers: they'll never know the URLs have changed.
If your website drops in the rankings, don't revert back to the old navigation.
By going BACK to the old navigational structure of your "old" website, the one Google has already indexed, will just prolong things. Plus, it'll take additional time – and cost – for the web design company to revert back to the old navigation. And the old URLs might not even make sense in the new website. So if your new website, with the new navigation (and new URLs), have been in existence for a while, going backwards isn't realistic.
Plan ahead, and you won't have nay issues with yournew website ranking where it was before the redesign.