Redirects during a migration: how to keep your Google rankings
How to map every old address to a new one when a website moves, so rankings, backlinks and bookmarks survive the change.
The short answer
Search engines rank individual addresses, and other websites link to individual addresses. When a website moves or is rebuilt, addresses change, and an address that changes without a redirect loses its ranking, its backlinks and every bookmark that pointed at it. The protection is a permanent redirect from each old address to its closest new equivalent, which tells search engines the page has moved and passes the ranking signal along. The work is a redirect map: a list of every old address, built from a crawl of the old site and the addresses that receive traffic and links, each paired with its new destination. The map is tested before the switch, deployed with the new site and kept for at least a year, in practice indefinitely. Redirect to equivalents, not to the home page, and let genuinely removed pages return a proper not-found status.
Building the redirect map
| Source of old addresses | Why it matters |
|---|---|
| A crawl of the old site | Every address the site itself links to |
| Analytics: pages with visits in the last year | The addresses people actually reach |
| Search console: pages with impressions and the pages with backlinks | The addresses that carry ranking and links |
| The old sitemap | Addresses the site declared |
| Marketing materials, print, email signatures, ad campaigns | Addresses people type or scan |
| Old redirects already in place | Chains to collapse into single hops |
Each address gets one destination: the same content at its new address, or the closest related page. The map is a plain list, kept in the repository with the site, so it is versioned and reviewed like everything else.
Doing it properly
- Freeze the old structure: export the full address list before anything changes.
- Map each address to its new destination, equivalents first, categories for removed pages.
- Collapse chains: if an address already redirected somewhere, point it straight at the final destination.
- Handle patterns with rules where the change is systematic, such as a folder rename, and list exceptions individually.
- Deploy the map on the new platform so redirects are served at the edge, before the switch.
- Test every entry automatically: request each old address and confirm the status and destination.
- Submit the new sitemap and, for a domain change, use the search console’s change-of-address tool.
- Watch not-found reports in the search console for weeks afterwards and add redirects for anything missed.
Details that matter
Trailing slashes, uppercase letters, file extensions and query strings all create address variants; the redirect rules must handle each consistently. Images and documents have addresses too, and linked PDFs in particular often carry backlinks. Internal links on the new site should point at the new addresses directly, not rely on redirects. And the old domain, if the domain changes, must be kept and redirected for as long as the business can afford the renewal, which is usually forever at the price of a domain.
What this means for you
Treat the redirect map as a launch deliverable equal to the site itself: every old address that had traffic or links, paired with its closest new equivalent, tested before the switch and kept indefinitely. Rankings and backlinks survive a migration done that way and are lost in one done without it, and the difference shows up in traffic for the following year.
Frequently asked questions
We are keeping the same domain. Do we still need redirects?
Yes, if any address changes. A rebuild usually changes structure: new paths, different slugs, merged or removed pages, a change from trailing slashes to none or from file extensions to clean paths. Every changed address needs a redirect. If the domain and every path stay identical, no redirects are needed, which is rare in practice.
How long should the redirects stay in place?
At least a year, and in practice indefinitely for addresses with backlinks, because the links on other sites never update themselves. Redirects cost nothing to keep on a modern platform, so the sensible policy is to keep the map permanently and add to it whenever an address changes again.
What about pages we are deliberately removing?
Redirect them to the closest related page if one exists: a removed service to its category, an old article to the updated one. If nothing is related, let them return a proper not-found status with a helpful page, rather than redirecting to the home page. Search engines handle a genuine removal correctly; they treat a mass redirect to the home page as removal anyway, while confusing visitors.
Sources
- Google Search Central: Redirects and Google Search (accessed 2026-09-12)
- Google Search Central: Site moves with URL changes (accessed 2026-09-12)