HTTP 3xx status code
301 Moved Permanently
301 Moved Permanently is how the web says a page has changed address for good. When a client asks for the old URL, the server replies with a 301 and points to the new one, and browsers and search engines update accordingly. The old address is meant to be retired, and future requests should go straight to the new location.
The permanence is the whole point, and it is what separates a 301 from its temporary cousin, the 302. A 301 tells everyone that the change is not coming back, so browsers may cache it and skip the old URL entirely next time, and search engines transfer the old page’s standing to the new one. That last part is why 301s matter so much for anyone who cares about search traffic: done properly, moving a page or merging two pages keeps almost all of the ranking value that the old URL had built up.
Because of that, the 301 is the workhorse redirect of the web. Renaming a page, switching a whole site from one domain to another, moving from http to https, or forcing a single canonical address are all jobs for a 301. The main thing to get right is to only use it when the move really is permanent, since browsers and search engines will take the signal at its word.
Frequently asked
What is a 301 redirect?
A 301 redirect is a permanent redirect. When a browser or search engine requests the old URL, the server responds with 301 and the new address, and the client goes there instead. It signals that the move is permanent, so the old URL should be forgotten.
Should I use a 301 or a 302 redirect?
Use a 301 when the move is permanent and you want the new URL to replace the old one, which is almost always the case for a changed address. Use a 302 only when the move is genuinely temporary and the original URL will return.
Do 301 redirects affect SEO?
Yes, in a good way when used correctly. A 301 passes most of the old page's ranking signals to the new URL, so it is the standard way to move or merge pages without losing search visibility.