Every page on your website has an address, and sooner or later some of those addresses change. You rename a service, retire a product, restructure the site, move to a new domain. A 301 redirect is how you move house without losing your mail: it forwards visitors and search engines from the old URL to the new one, permanently, and carries the old page's hard-earned rankings with it. Skip that step and the traffic, links and authority attached to the old address simply leak away. Here is when to use a 301 redirect, when not to, and the mistakes that quietly cost sites their rankings.
What a 301 redirect actually is
When a browser or crawler requests a URL, your server answers with a status code. 200 means "here is the page". 404 means "nothing here". A 301 redirect means "this page has moved permanently, go here instead", and the visitor is passed straight to the new address, usually without noticing. Search engines treat that signal seriously: Google transfers the old URL's indexing signals, including the value of its backlinks, to the destination, and over time replaces the old address with the new one in its index.
That transfer is the whole point. Redirect SEO is not about gaining anything new; it is about not losing what a page has already earned. A URL that has collected links and rankings for five years is an asset, and a 301 redirect is the paperwork that transfers the asset to its new address.
301 vs 302: pick the right one
The 301 redirect has a sibling, the 302, which means "moved temporarily". The practical difference: a 301 redirect tells Google to index the destination and consolidate signals there for good, while a 302 says the original address will return, so keep it in mind. Choosing between 301 vs 302 is simple once you ask one question: is the old URL ever coming back? If not, use a 301 redirect. If it genuinely is, such as a page parked during maintenance or a seasonal campaign URL, use a 302. Google has said it treats long-lived 302s as permanent eventually, but "eventually" is doing a lot of work in that sentence; sending the clear signal from day one is free.
When you need a 301 redirect
The everyday cases: you change a page's URL, even slightly, because to Google a new URL is a new page. You delete a page that has traffic or backlinks, and redirect it to the closest relevant page still standing. You merge two thin pages into one stronger one. And you fix broken links you cannot edit directly, such as an external site linking to a URL that no longer exists; a 301 redirect catches that lost visitor mid-flight. Trailing-slash changes, uppercase-to-lowercase URL clean-ups and date-stamped blog URLs being tidied all belong in the same bucket: if the address changes, the redirect goes in.
The big-ticket cases: moving from http to https, switching between www and non-www, changing domain names entirely, or relaunching the site on a new platform where every URL changes shape. In a migration, the redirect map, the spreadsheet pairing every old URL with a 301 redirect to its new home, is the single most important SEO deliverable. Sites that skip it can lose rankings overnight, which is why it is a fixture in our technical SEO checklist and our SEO audit process.
Redirect to equivalents, not the homepage. Sending every retired URL to your homepage looks tidy but wastes the transfer: Google treats irrelevant mass redirects much like 404s. Old service page to new service page, old product to nearest category, like for like.
How to set one up
You rarely need to touch code. On WordPress, redirect plugins such as Redirection or the redirect modules in the big SEO plugins handle it from a simple old-URL-to-new-URL form. Shopify has native URL redirects under its navigation settings. Most hosting control panels offer a redirect tool, and if your site sits behind Cloudflare, redirect rules live there too. Under the hood these all do the same thing: return a 301 status and the new location.
After setting one up, verify it. Paste the old URL into your browser and confirm it lands on the right page, then check the status code with any free header checker, or watch Google Search Console pick up the change. Guessing is how redirect problems survive for years.
One more piece of housekeeping: leave each 301 redirect in place for the long haul. Google's guidance is to keep redirects live for at least a year so its systems fully transfer the signals, and visitors keep following old bookmarks and stale links for far longer than that. Redirects are close to free to keep; deleting them early is how transferred value quietly falls back out of the bucket.
The mistakes that cost rankings
Redirect chains are the most common: A redirects to B, then someone later redirects B to C, and eventually a URL takes four hops to resolve. Each hop slows the visitor and wastes crawl attention, and Google stops following after a limited number of hops. Point every old URL at its final destination with a single 301 redirect. Redirect loops, where A eventually points back at A, break the page outright. And the quietest mistake is the missing redirect: deleting pages during a redesign and leaving the old URLs as 404s, orphaning every backlink they had. A crawl of your site, plus the broken links your technical SEO tools surface, will find all three.
If you are planning a redesign or migration and the redirect map sounds like the part you would get wrong, that is a reasonable instinct; it is the part most people get wrong. Our technical SEO service builds and verifies redirect maps as standard, and we are happy to sanity-check yours before you flip the switch.
