What is a 301 redirect?

A 301 redirect is a method of sending both users and search engines to a new URL when the original URL has been changed. The status code “301” signals that the move of the URL is permanent.

301 redirect: a permanent redirect sending users and search engines from the old URL to the new URL

That is important, because it helps search engines understand that the old URL has been permanently replaced by a new one and that they should update their search result entries accordingly. A 301 redirect is often used to make sure that links pointing at the old URL do not lose their value and are passed on to the new URL instead. That is decisive for preserving link authority and search engine rankings.

How do I set up a 301 redirect?

Setting up a 301 redirect works in several ways, depending on the server software you use. On Apache web servers the redirect is usually set up in the .htaccess file, where you add the following line:

Redirect 301 /old-url https://www.example.com/new-url

On Nginx servers you set it up in the server configuration file. Here is an example of how the redirect is written:

server {
    ...
    location /old-url {
        return 301 https://www.example.com/new-url;
    }
    ...
}

If you work with a content management system (CMS) such as WordPress, plugins make setting up 301 redirects easier: they offer a user friendly interface that lets you create redirects directly in the admin area.

When do 301 redirects matter for SEO?

301 redirects are decisive for search engine optimization (SEO) for several reasons. First, they help preserve the link juice (the authority that is passed on through links) and the ranking of a page when the URL of that page is changed. That matters especially when you restructure a website and old URLs are no longer in use.

Second, they prevent the problem of duplicate content, because they make sure that search engines and users are sent to the current version of a page, even when they could reach it over several different URLs. Finally, 301 redirects improve the user experience: visitors do not land on error pages (404 errors) but are redirected to the page they were looking for. Redirect chains, stale targets and forgotten old URLs are among the first things an SEO audit brings to light.