301 redirect
permanent redirect / 301 / HTTP 301
A 301 redirect is a server instruction saying a page has permanently moved to a new address. Google treats it as a signal that the new address is the real one and should be the version shown in search results. A 302 says the move is temporary, so Google keeps showing the old address instead.
When a page changes address, something has to tell every browser and every search engine where it went. A 301 is that message, and the number is literally the code the server sends back. The standard that defines it, RFC 9110, puts it in one line: the target resource has been assigned a new permanent URI, and future references ought to use the new one.
The reason this matters to you rather than to your developer is what Google does with it. Google says that for a permanent redirect its indexing pipeline uses the redirect as a signal that the redirect target should be the canonical address, meaning the one it shows in results. For a temporary redirect, Google says the opposite: it follows the redirect but does not use it as that signal. So a 302 on a permanent move leaves Google showing your old address indefinitely. The pages still work for anybody who clicks, which is exactly why this goes unnoticed for months.
Google's own recommendation is short. If you need to change the address of a page as it appears in search results, use a permanent server side redirect whenever possible. On the worry everybody raises, Google is equally direct in its site move guidance: permanent redirects do not cause a loss in PageRank.
There is a second code worth knowing, because 301 has a quirk. Mozilla's documentation notes that with a 301 or 302, a GET request is unchanged but other methods may or may not be changed to GET, and that 308 and 307 were created specifically to remove that ambiguity. For an ordinary page move a 301 is fine. For anything that submits data, 308 is the safer permanent code.
In practice
A dealership rebuilds its site and every service page gets a new address. Done with 301s, the rankings those pages had follow them across. Done with 302s, Google keeps showing addresses that now bounce through a redirect, and the new pages look brand new to it. Same visitor experience on the day, very different outcome three months later.
Not the same as
- A 302 redirect
- Same mechanism, opposite meaning. Use it only when the old address is genuinely coming back.
- A 404
- A redirect sends somebody somewhere. A 404 tells them the page is gone and leaves them stuck.
Why it matters to you
Redirects are the single most common way a site redesign quietly costs a business its search traffic. Everything looks fine, because every link still works. The damage only shows up in the rankings, weeks later, by which point nobody connects the two events.
What to ask or check
- 01Are the redirects on this move 301s, and can I see the list of old address to new address?
- 02Does any old address redirect to a page that then redirects again?
- 03What happens to a page we delete rather than move?
What people get wrong
That a redirect loses you your rankings. Google states plainly that permanent redirects do not cause a loss in PageRank. The damage comes from using a temporary redirect for a permanent move, or from chaining redirects together.
Red flags
- A redesign quote that does not mention redirects at all.
- Old addresses that redirect to the home page rather than to the page that replaced them.
- A chain of redirects. Google can follow up to ten hops but advises going straight to the final destination, ideally no more than three and fewer than five.
Where you will see it
In your hosting or server configuration, in a redirects file, and in Search Console when an old address is reported as having moved.
Where we fit
Building and moving websites is one of the things we do, and mapping old addresses to new ones is part of that work rather than an extra.
See how we do it