Replatforming without losing traffic: a checklist
Traffic loss during a replatform is almost never caused by the new platform. It is caused by addresses changing without redirects, content disappearing along the way, or the new site not being indexable. All three are predictable and therefore avoidable, but only if the work happens before launch rather than after.
What should be measured before you start?
You cannot know whether you lost traffic without a before. Capture this while the old site is still live:
- Every address receiving organic traffic, from Search Console, at least twelve months back.
- Rankings for the most important queries.
- The number of indexed pages.
- Pages with inbound links from other sites. Those are the most expensive to lose.
When should the redirect map be written?
One row per old address with its new equivalent. Not "everything to the home page", which counts as a soft 404 and throws the signal away. Where no equivalent exists: point at the nearest relevant page, or return 410 if the content genuinely is gone. The map should be finished before development starts, because writing it usually surfaces content nobody remembered to migrate.
Can the new site be indexed?
Fetch a page from the new site without executing JavaScript, with curl for instance. If the body copy and links are in the response, the foundation is sound. If the response is an empty element filled in by a script, several crawlers see nothing, and several AI crawlers execute no JavaScript at all. This test takes thirty seconds and saves projects.
What happens on launch day?
In this order:
- Check robots.txt is not blocking the whole site. The single most common post-launch mistake.
- Check noindex was removed from production. The second most common.
- Test a sample of the redirect map against the live site, not staging.
- Submit the new sitemap in Search Console.
- Keep the old sitemap reachable for a couple of weeks, so the crawler finds the old addresses and sees the redirects.
How long until traffic comes back?
Expect a dip. Indexing takes time and rankings move before they settle. Read the coverage report in Search Console weekly: pages suddenly classed as soft 404s or duplicates are the signal that something in the redirects is wrong. If traffic has not returned after six weeks, the answer is not patience, it is debugging.
What gets forgotten most often?
Structured data does not migrate automatically. Neither do canonical addresses, hreflang if you run multiple languages, or the redirects the old site already carried from an even older one. That last one is easy to miss and produces a chain of hops that loses signal at every step.
Common questions
How long until traffic returns after a replatform?
Expect a dip of a few weeks while indexing catches up and rankings settle. If traffic has not returned after six weeks, the answer is not patience but debugging: read the coverage report for pages suddenly classed as soft 404s or duplicates, because that is the signal the redirects are not doing what was intended.
Should we change domain at the same time as the platform?
Preferably not. Risk in a migration follows how many things change at once, not the platform change itself. Change domain, URL structure, content and technology in one launch and you cannot tell what caused a drop. Do the domain move before or after, with a few months in between.
Can we just point every old address at the home page?
No, that counts as a soft 404 and throws the signal away. A redirect should go to the page equivalent to the old one. Where no equivalent exists: point at the nearest relevant page, or return 410 if the content genuinely is gone, which is a clearer answer than a redirect to something that does not address the question.
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