What is a 301 redirect?
A 301 is a status code that means moved permanently. When a browser asks for the old address, the server answers with the new one and the browser follows it without the visitor noticing. Search engines treat it as a forwarding address: over time they drop the old URL from the index, keep the new one, and pass along most of the link equity the old page had earned. It is the standard tool for any change of address on the web, from a single renamed page to a whole domain migration.
The number is less important than the word permanent. A 301 tells the world not to come back to the old URL, ever, so it belongs on moves you mean, not on experiments.
Why it matters
Why a 301 redirect matters
Links are an asset. Every press mention, every partner link, every bookmark pointing at a page you have renamed is worth something, and without a redirect all of it lands on a 404. A 301 keeps that value alive through a redesign, a rebrand or a platform change, which is the difference between a site migration that holds its rankings and one that loses a year of growth overnight.
It also protects the brand experience. A campaign QR code printed on packaging last year, a URL on a trade show banner, an old link in an email: all of them should still arrive somewhere sensible. A 301 is how a brand keeps its promises after the page has moved.
In practice
How a 301 redirect works in practice
- 01
Map first, redirect second. Before a migration or a restructure, list every old URL alongside the new URL it should become, one to one wherever possible. Redirecting everything to the homepage is the lazy version, and search engines treat a mass redirect to an unrelated page as a soft 404. The mapping lives in the server configuration, a redirect plugin or the CDN, and it goes live at the same moment as the new URLs.
- 02
Then you check it. Crawl the old URL list after launch to confirm each one returns a single 301 to the right destination, with no chains and no loops. Keep the redirects in place for the long term, because search engines and other sites take months to catch up, and a redirect removed too early sends everyone back to the error page you were avoiding.
Watch out
What people get wrong about 301 redirects
Chains. A page that was redirected in 2019, redirected again in 2022 and again this year sends every visitor through three hops, slows the page and leaks equity at each step. Redirect the original URL straight to the final destination and collapse the chain. The other mistake is confusing a 301 with a 302: a temporary redirect used for a permanent move leaves the old URL in the index for far longer than you intended.
And removing them. Redirects are not clutter; they are the memory of every address your site has ever had. Audit them, collapse the chains, but keep the ones that still receive traffic.
