301 redirect
A 301 redirect is an HTTP response telling browsers and search engines that a page has moved permanently to a new address, sending visitors there automatically and transferring its search signals.
The number comes from the HTTP status code 301 Moved Permanently. A 302 Found or 307 Temporary Redirect says the move is temporary, so search engines usually keep the old URL in results. A 308 Permanent Redirect is treated like a 301. Use a permanent redirect only when the old address will not come back.
Google has said that permanent redirects do not lose ranking credit, so the old fear of a percentage of value disappearing with each redirect no longer applies. What still hurts is a chain of several redirects, or a redirect pointing at an unrelated page.
How it works
When a browser requests the old URL, the server answers with status 301 and a Location header naming the new URL, and the browser loads that instead. Search engines see the same response, treat the new address as the canonical and move links and other signals to it over time.
Redirects are set on the server or in the CMS: in an .htaccess file on Apache, in the web server configuration, through a plugin or in a hosting dashboard. Google's guidance for site moves is to keep redirects in place for a long time, generally at least a year. Redirects apply to visitors too: browsers remember permanent redirects, so testing in a fresh private window avoids being fooled by an old cached result.
Redirects should be one hop where possible. If page A was redirected to B and B later moves to C, update A to point directly to C. Google follows a limited number of hops in a chain before giving up, and every hop slows visitors down. Redirecting from HTTP to HTTPS and from non-www to www, or the reverse, should also happen in a single step. A redirect loop, where pages point back to each other, makes a page unreachable.
Example
A clinic renames its pages from /services.php?id=4 to /services/teeth-whitening/. Without redirects, every old link from Google, other sites and patients' bookmarks would hit a 404 error. It maps each old URL to its exact new equivalent with a 301. Rankings usually settle on the new addresses within weeks, and nobody lands on a dead page.
Before launch, the clinic exports every old URL from Search Console's Performance report and its old sitemap, and maps each one to a new address in a spreadsheet. After launch, it pastes old URLs into a redirect checker or a site crawler in list mode to confirm each returns a single 301 to the right page. Search Console's Page indexing report then shows any old addresses still returning errors.
Why it matters for your business
Redirects protect the value built up in old URLs during a redesign, domain change or migration. Skipping them is one of the most common reasons a new site loses traffic after launch. The cost is a careful URL map before launch, which is far cheaper than recovering lost rankings later. The work scales with the size of the site, but even a large map is mostly a spreadsheet exercise.
Common mistakes
- Redirecting every old URL to the home page instead of to its closest matching new page.
- Using a temporary 302 redirect for a move that is actually permanent.
- Creating chains where one redirect points to another, and another, before reaching the final page.
- Removing redirects a few weeks after a migration, while old links and bookmarks still use them.
Questions people ask
What is the difference between a 301 and a 302 redirect?
A 301 means the page has moved permanently, so search engines replace the old URL with the new one in results and transfer its signals. A 302 means the move is temporary, so they usually keep showing the old URL. Use 301 for redesigns and domain changes, 302 for short-term moves.
Do 301 redirects hurt SEO?
A single, correct 301 to the equivalent new page does not lose ranking credit, according to Google. Problems come from redirect chains, loops, redirecting to irrelevant pages or to the home page, and removing redirects too soon. Done properly, redirects are what preserve SEO through a site change.
How long should I keep 301 redirects?
As long as practical. Google advises keeping redirects for at least a year after a site move, and many sites keep them indefinitely because old links and bookmarks keep sending visitors. Redirects cost almost nothing to maintain, while removing them turns old traffic into errors.
