Website migration without losing SEO: a step-by-step guide for a redesign, new CMS or new domain

What a website migration is, and why not all migrations are alike

“Migration” means any change that can alter how Google sees and understands a site: new addresses, a new structure, a new platform, a new domain or a new server. The more things change at once, the greater the risk.

A practical rule: if you can avoid changing several things at the same time, do so. A rebrand with a new domain, a new platform and rewritten content is a complicated migration; unless it is essential, split it into stages.

Why traffic is actually lost in migrations

Losses do not happen because Google “punishes” change. They happen when Google can no longer find or understand what it used to find. The causes repeat:

• Old addresses without a redirect. Pages that had rankings and incoming links return a 404 error; the rankings are lost and external links no longer pass on any value.
• Wrong redirects. Every old page sent to the home page, or chains of redirects (A to B to C).
• Blocks left over from testing. A “noindex” tag or a “Disallow: /” rule in robots.txt, forgotten from the staging site.
• Lost or thinned content. Shortened texts, changed headings, sections removed for no good reason.
• Broken internal links. The new navigation no longer connects the important pages to each other.
• A slower site. A new design loaded with scripts can end up slower than the old one.
• Tracking that disappeared. Without analytics, you see neither the loss nor its cause.

Nothing in this list is mysterious; every point can be foreseen and checked. That is why a well-run migration is recognised mostly by the absence of drama.

Before the migration: inventory and baseline measurements

You cannot compare “after” with “before” if you did not note down “before”. Preparation is the dullest part and the most valuable.

1. Crawl the whole site. Export the list of all addresses with title, description, headings, response codes and internal links.
2. Collect performance data. From Google Search Console: pages and queries with impressions and clicks over the last 12 to 16 months. From analytics: pages with visits and conversions.
3. Identify the critical pages. Those that bring traffic, leads, orders or links from other sites. These must not be lost.
4. Record the technical set-up. Existing redirects, the XML sitemap, robots.txt, structured data, hreflang (if you have multiple languages) and canonicals.
5. Save a complete copy. Files and database, in a safe place.
6. Decide what happens to each page. It stays, moves, is merged with another or is removed.

If you are still deciding on the platform, our guide to WordPress versus a custom website helps you choose before the migration begins.

The URL map and 301 redirects: the core of the operation

A URL map is a table with two columns: the old address and the new address that replaces it. The 301 redirects, which are permanent moves, are configured from it, telling browsers and search engines that the page has moved for good.

Rules that avoid most problems

• Redirect to the closest equivalent page, not to the home page for the sake of it. Google may treat redirects to unrelated pages as soft 404 errors.
• One hop only. From the old address straight to the final one, with no chains.
• Use 301 for permanent moves. A 302 is for temporary situations and sends a different signal.
• Keep redirects for long enough. Google’s usual recommendation is at least a year, and for pages with valuable external links, as long as you can.
• Do not forget the variants. With and without “www”, with and without a trailing slash, capital letters, tracking parameters.

The staging site: what to test before you press the button

The new site is built and checked in a separate environment, not at the public address. That environment must be closed to search engines and protected with a password; otherwise Google may index an incomplete copy and create duplicate content.

In testing, go through at least the following:

• the redirects in the map, first on a sample and then in full, using a bulk checking tool;
• titles, descriptions and headings on the critical pages, compared with the old version;
• internal links, images, forms and call buttons;
• structured data, the XML sitemap and a robots.txt prepared for production (not the test one);
• speed on mobile and desktop; see our guide to Core Web Vitals;
• conversion tracking, meaning the tags and events in analytics; the details are in our article on conversion tracking with GA4 and Meta Pixel;
• how the results will look in Google; you can preview how titles will appear with the SERP snippet preview.

Launch day: the order of operations

Choose a day and time with lower traffic, not in peak season and not on a Friday evening. The team must be available for several hours afterwards.

1. Lower the DNS time-to-live (TTL) a day or two beforehand so the change propagates quickly. Server choice is covered in our guide to choosing web hosting.
2. Check the HTTPS certificate on the new server.
3. Put the new site live and remove the password protection.
4. Remove “noindex” and any robots.txt blocks that were active during testing. This is the most common mistake, so check it twice.
5. Activate the 301 redirects and immediately test the most important old addresses.
6. Submit the new XML sitemap in Search Console.
7. Work through the launch checklist for forms, tracking, cookies and error pages.

After launch: the first 30 to 90 days

The work does not end at launch. Monitor daily during the first week, then weekly.

• Search Console: the page indexing report, 404 errors, redirect warnings and page performance. Compare with the baseline figures.
• Analytics: organic traffic, conversions and landing pages. A moderate initial dip may appear because Google is reprocessing the site.
• A fresh crawl: run the crawler again and look for new errors, redirect chains and orphan pages.
• External links: if you can, ask important partners to update their links. The redirect helps, but a direct link is cleaner.
• Domain change: Search Console has a dedicated tool (Change of Address), available only for domain moves. Check the current requirements in the interface; typically both domains must be verified and the 301 redirects must be live.

Fluctuations lasting a few weeks are common in large migrations. If critical pages do not recover within a reasonable period, look for the cause systematically: redirects, indexing, content, speed. Official information on site moves can be found in the Google Search Central documentation.

Which technical SEO elements you must keep

A good-looking redesign can lose the ground it gained if it ignores the basics. Keep or improve:

• Titles and descriptions of pages that already rank; change them only for a clear reason.
• Heading structure (H1, H2) and the body text. Good text does not get better by being replaced with images.
• Internal links to important pages.
• Canonical and hreflang tags, if you have several languages.
• Existing structured data (for instance for the business, products or articles).
• Images with alt text and descriptive file names.
• Speed and the mobile experience.

SEO itself is the field of our separate brand, Succes SEO, which can check the redirect map and indexing after launch.

Common migration mistakes

• Skipping the inventory of the old site. Without it, you do not know what you have lost.
• Sending every old address to the home page. You lose the relevance of each page.
• Forgetting “noindex” on the staging site. The new site stays invisible.
• Launching on a Friday evening without a plan. Problems appear over the weekend, when nobody is watching.
• Removing “old” content without measuring it. Some simple pages bring steady traffic.
• Not testing conversion tracking. You find out two weeks later that you have no data.
• Changing everything at once. Domain, design, text, structure: you can no longer isolate the cause if a drop appears.

How we approach it

We start from the inventory and the purpose of the migration: what must change and what must stay. We build the URL map together with the client, prepare the new site in a protected environment, test the redirects and tracking, then launch in a planned window and monitor for weeks. We do not promise “zero fluctuation”, because nobody can; we promise to avoid the losses that can be avoided.

If you need a site built to your requirements, or a move away from a limited platform, you can read more about our custom website development or about custom CRM systems and platforms. And for existing WordPress sites, WordPress maintenance is useful both before and after a move.

In short

• Losses happen when Google can no longer find or understand the old pages, not because of change in itself.
• Record the starting position: addresses, traffic, critical pages and technical set-up.
• A URL map and page-by-page 301 redirects are essential.
• Check “noindex” and robots.txt at launch.
• Monitor for 30 to 90 days and keep redirects for at least a year.