What a 301 redirect actually does
When someone requests an old URL, the server responds with an HTTP 301 status code and a new location. The browser follows automatically, so a visitor rarely even notices - they land on the new page, not an error. Search engines follow the same signal: a 301 tells them to transfer the old URL's ranking value to the new URL over time, rather than treating the new page as unrelated, brand-new content.
This is different from a 302 (temporary) redirect, which tells crawlers the move isn't permanent and that search value shouldn't be fully transferred. It's also different from a manual link update on your own site - a 301 catches everyone who still has the old URL bookmarked, linked from another site, or indexed in search results, not just people clicking links you control.
Why 301 redirects matter during a platform migration
Moving to a new platform almost always changes your URL structure, even when you try to keep it close - product URLs, category paths, and blog posts often end up in a different shape than before. Every old URL that search engines have indexed, and that other sites link to, needs a 301 pointing to its new equivalent, or you lose that page's accumulated ranking signal and send visitors to a dead end.
The risk isn't hypothetical: launch a new store without a redirect plan and you'll typically see 404 errors pile up, inbound links break, and organic traffic drop within days of going live, since search engines revisit indexed URLs quickly. A redirect plan built before launch, not patched together after traffic drops, is what keeps that from happening.
Getting redirects right, not just present
Having a 301 isn't enough on its own - it needs to point at the right target. Redirecting every old URL to your new homepage technically "resolves" the link but throws away the specific relevance a search engine or visitor was expecting. We map old URLs to their closest real equivalent on the new platform, and flag pages with no clean match instead of guessing.
We also check for redirect chains (URL A to B to C) and loops, which add latency and can cause crawlers to stop following the chain altogether. A clean migration ends with one hop per URL, not three.
Frequently asked questions
Is a 301 redirect the same as a URL change?
No - changing a URL without a redirect just breaks the old link. A 301 redirect is the instruction that connects the old URL to the new one, so anyone (or anything) that requests the old address is sent automatically to the new page.
Do 301 redirects fully preserve my search rankings?
They preserve most of the ranking signal associated with the old URL, but not automatically every position for every keyword - other factors like site quality and competition still apply. What a 301 reliably does is tell search engines the content moved, rather than letting them treat the new URL as unrelated.
How long do I need to keep redirects in place?
Indefinitely, or as close to it as practical. Old links from other websites, saved bookmarks, and print materials can keep sending traffic to old URLs for years, and search engines can take time to fully process a large batch of redirects.
What's the difference between a 301 and a 302 redirect?
A 301 signals a permanent move and passes ranking signal to the new URL; a 302 signals a temporary move, and search engines are more cautious about transferring that signal. For a platform migration, where the old URL isn't coming back, a 301 is almost always the correct choice.