Short answer: The key to avoiding SEO losses during a site migration is to connect every URL on the old site to its closest equivalent on the new site with a permanent (301 or 308) redirect. In addition, canonical tags on the new pages must be correct, the new sitemap must be submitted to Search Console, and 404 errors and the indexing report must be monitored closely in the weeks after the switch.
What counts as a "site migration"?
- Platform change: Moving from WordPress to Next.js, or from an off-the-shelf site builder to custom software
- URL structure change: For example,
/blog/articlebecoming/resources/article - Domain change:
oldsite.combecomingnewsite.com - Protocol change:
httpbecominghttps
If only the design changes and the URLs stay the same, the risk is lower, but preserving titles, content and internal links still matters.
What should be done before the migration?
- Build a list of the old URLs. Combine the old site's sitemap, the Pages report in Search Console and the most-visited pages in your analytics. URLs that receive external links are especially important.
- Prepare the redirect map. Write down the new equivalent for every old URL. Pages with no direct equivalent should be redirected not to the home page but to the page that is closest in topic.
- Preserve important content. The titles, body copy and FAQs of pages that bring in traffic should also appear on the new site.
- Record the current state. Note your rankings, traffic and the number of indexed pages before the migration; you will need these figures for comparison afterwards.
What does a redirect map look like?
| Old URL | New URL | Note |
|---|---|---|
| /hizmetler | /hizmetlerimiz | Section name changed |
| /hizmetler/yedekleme-antivirus | /hizmetlerimiz/yedekleme-siber-guvenlik | Service scope expanded |
| /blog/:yazi | /bilgi-merkezi/:yazi | Bulk rule |
| /projeler/eski-proje-adi | /projeler/yeni-proje-adi | URL shortened |
These examples are taken from the real redirects we implemented when moving dsabilisim.com (the Turkish site) to its new platform. Bulk rules can redirect thousands of URLs with a single line, but exceptions need to be written separately.
What are the most common mistakes during a migration?
- Redirecting everything to the home page: Google often treats this as a soft 404, and the value of the old page is not passed on.
- Using temporary (302) redirects: A permanent move should use 301 or 308.
- Redirect chains: Instead of consecutive redirects such as A → B → C, A should go directly to C.
- Loops: If rules for uppercase/lowercase letters or trailing slashes are written incorrectly, a page can redirect to itself and never load. After the migration, test every important URL one by one.
- Letting the staging site get indexed: The site under preparation should be blocked with
noindex, and you must make sure this tag is removed when you go live.
What should be checked after the migration?
- Request every URL in the old sitemap one by one and confirm that each redirects to the right place in a single hop.
- Submit the new sitemap to Search Console, and use the URL Inspection tool to request indexing for important pages.
- If the domain changed, use the Change of Address tool in Search Console. This tool is only needed for domain changes.
- During the first weeks, check the 404 and redirect errors in Search Console every day.
- Keep the redirects in place for at least a year, and indefinitely if possible. Removing redirects too early causes old links to lose their value.
Some ranking fluctuation in the first weeks after the switch is normal. In a properly executed migration, metrics usually return to their previous levels within a few weeks. If you are setting up Search Console for a new site for the first time, take a look at our Search Console guide as well.
Thinking about rebuilding your website? With our modernization and SEO / GEO / AEO services, we plan the migration together with you, from the redirect map all the way to post-launch monitoring.
Sources
Frequently Asked Questions
Google recommends at least one year. If other sites link to the old URLs, keeping the redirects indefinitely is the safest option.
Both are permanent redirects, and Google treats them the same way. Technically, 308 differs in that it preserves the request method (such as POST).
First check that the old URLs redirect correctly, that the new pages return a 200 status and that no noindex tag has been left in place by mistake. The Pages report and the 404 list in Search Console usually reveal the source of the problem.