What Is a 301 Redirect and When Should You Use One?

A 301 redirect is one of the most important tools in both web development and search engine optimisation. It tells browsers and search engines that a URL has permanently moved to a new location — and instructs them to update their records accordingly.

Used correctly, 301 redirects protect your SEO rankings when URLs change. Used incorrectly — or not used at all — they can cause rankings to evaporate. This guide explains exactly what they are, how they work, and when to use them.

How 301 Redirects Work

When a browser or search engine bot requests a URL that has a 301 redirect, the server responds with a 301 status code and the new destination URL. The browser immediately loads the new URL. For users, this happens invisibly in under a second.

For search engines, a 301 signals that the original URL no longer exists at that location and that all its associated value — inbound links, ranking history, crawl data — should be transferred to the new URL. This transfer of "link equity" is not instantaneous; Google typically processes it over several weeks.

A 302 redirect, by contrast, signals a temporary move. Search engines do not transfer link equity via 302s — they keep indexing the original URL on the assumption it will return. Using a 302 when you mean a 301 is a common and costly mistake.

When to Use a 301 Redirect

Use a 301 redirect whenever a URL permanently changes location. The most common scenarios are: changing a page’s URL slug (e.g., from /services/web-design-norwich to /web-design-norwich), moving a website to a new domain, migrating from HTTP to HTTPS (though modern servers usually handle this automatically), and removing a page that has inbound links or traffic.

Always redirect both www and non-www versions of your domain to a single canonical version. If your site is www.example.com, make sure example.com redirects to it (or vice versa). Google treats these as separate URLs without a redirect in place.

When you delete a page that was receiving organic traffic, redirect it to the most relevant existing page. If there is no direct equivalent, redirect to the parent category. A redirect to the homepage is better than a dead 404, but a contextually relevant redirect is significantly better.

What to Avoid

Redirect chains occur when URL A redirects to URL B which redirects to URL C. Each hop in the chain reduces the link equity passed and slows down page loading. Keep redirect chains to a maximum of one or two hops, and periodically audit for chains that have built up over time.

Redirect loops occur when URL A redirects to URL B which redirects back to URL A. Browsers will show an error; search engines will stop following the chain. These are usually caused by configuration errors in .htaccess files or CMS redirect plugins.

Do not use 301 redirects for temporary situations — use 302 or 307 instead. If you are redirecting a promotional page that will return next month, a 301 will transfer the link equity permanently. When the original URL comes back, it will start fresh without its historical ranking signals.