SEO migration: changing platform without losing your rankings
Changing CMS or doing a full redesign is the point of maximum risk for search traffic. Not because the new site is worse, but because URLs, structure and markup all change at once, and the search engine has to reassess everything simultaneously.
The good news: the losses are almost always predictable and preventable. The bad news: fixing them after the move costs more than preparing.
Before the move
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Export every indexable URL from the old site — from Search Console, Yandex Webmaster, the sitemap and the server logs. All of them, not just the ones in the menu.
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Flag the pages with traffic and links. What happens to those matters more than the rest.
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Build a mapping of old URL → new URL. Every old URL needs a decision: moves, merges, or is removed.
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Record baseline metrics: impressions, clicks, positions on key queries, number of indexed pages.
Redirect rules
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301, not 302 — a temporary redirect doesn't pass accumulated weight.
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Straight to the final URL, without chains through intermediate ones.
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To a relevant page, not the homepage. Mass-redirecting everything to the homepage is read as content removal.
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Removed content with no replacement is more honestly served as a 404 or 410.
What travels with the pages
Titles and descriptions — often lost in migration, leaving the site with identical meta tags on every page. H1 headings, image alt text, structured data, internal links. Separately: on a multilingual site, hreflang has to be rebuilt around the new URLs, or the language versions stop being connected to each other.
On the day
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Test a sample of old URLs — do they redirect where they were meant to.
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Confirm robots.txt doesn't block crawling and didn't arrive from staging.
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Submit the new sitemap to both webmaster consoles.
Afterwards
Positions usually fluctuate for the first few weeks — that's normal and not a reason to roll back. Watch something else instead: whether crawl errors are increasing, whether pages are dropping out of the index, whether traffic held on the pages that were producing it. Comparing against the pre-migration baseline after a month gives an honest answer on whether the migration went well.
An expected dip for 2-4 weeks is routine. A dip that hasn't recovered after two months means something in the URL mapping was wrong.
If a platform change or redesign is coming up, we can prepare the redirect map and check the site before and after the move.