Migration recovery is the work of finding and reversing what went wrong when a replatform, redesign or domain change cost you organic traffic. It differs from other recovery work in one useful respect: you already know when it started and roughly what changed.
That makes it among the more tractable declines to diagnose, provided the investigation starts with the migration rather than with theories about updates or penalties.
Preventing this is covered on SEO migration, which is considerably cheaper than what follows.
The faults, in the order they are usually found
Unmapped URLs
The most common cause by a wide margin. The redirect map covered the pages someone remembered, and the long tail returns 404. Those pages were often a large share of total traffic.
- Reconcile old URLs from Search Console, analytics and any archived crawl against the new site.
- Search Console will list URLs returning 404 that you may never have inventoried.
- Check backlink data, since externally linked URLs matter disproportionately.
Redirects to the wrong destination
Everything unmatched pointed at the homepage. This is treated as a soft 404 rather than a redirect, so the signal is discarded rather than transferred.
Staging directives shipped live
A sitewide noindex or a robots.txt Disallow carried across from the staging build. This produces a sharp, broad collapse and is the fastest thing to rule out. See noindex tag issues.
Redirect chains
Old URL to interim URL to final URL. Each hop dilutes and slows the transfer, and chains are easy to create accidentally during bulk imports.
Content quietly shortened
Templates were rebuilt and copy was trimmed in the process. Pages that ranked on depth now have less of it, and nobody logged the change because it was a design decision rather than a content one.
Internal links still pointing at old URLs
Every internal path now runs through a redirect, which slows crawling and weakens the structure the new site depends on.
Working through it
- Fix directives first. Anything actively removing pages from the index takes precedence over everything else.
- Then complete the redirect map. Recover the unmapped URLs, mapping each to its closest equivalent rather than to the homepage.
- Then flatten chains, so every redirect resolves in one hop.
- Then repoint internal links at final destinations.
- Then compare content between old and new versions of the pages that lost most.
- Then revalidate, re-crawling and using URL Inspection on representative pages.
Working in that order matters. Restoring content on a page that is still noindexed achieves nothing, and it makes the next diagnosis harder.
What you need to hand
- The launch date, precisely.
- The old URL inventory, or whatever survives of it.
- The redirect map as implemented, not as planned.
- An archived crawl of the old site, if one exists.
- Search Console and analytics access covering both periods.
Where no old crawl exists, the Wayback Machine and Search Console historical data can partially reconstruct it. That reconstruction is usually the most time-consuming part of the engagement, and it is entirely avoidable by crawling before you migrate.
Frequently asked questions
How long after a migration should we worry?
A shallow dip recovering over two to four weeks is normal. A decline still deepening after three weeks, or one deeper than about thirty percent, warrants investigation now rather than more patience.
Can we recover fully?
Frequently yes, where the cause is mechanical, such as unmapped URLs or a directive fault, and it is corrected while the old signals persist. The longer a page returns 404, the more decay there is to reverse.
Is it too late if the migration was months ago?
Not too late, but harder. Signals decay and competitors take the positions. The work is the same; recovery is slower and less complete than it would have been at week two.
Should we roll back?
Rarely. A rollback is another migration with its own risks, and it usually compounds the problem. Fixing forward is almost always the better path unless the new site is fundamentally broken.
Consulting CTA
If your traffic fell after a replatform or redesign and has not recovered, book an SEO consultation to work through redirects, directives and content differences against the old site.