A 301 redirect is an instruction that tells a browser: “The requested page is no longer available at the URL you have, you’ll find it at this new new address”. The browser is then automatically redirected to this new URL and the desired, relocated content is displayed.
Why 301 redirects are so important for SEO
301-redirects are considered the best practice for SEO and inbound marketing. It is also Google’s recommended solution for any URL changes.
When a page is removed or moved, not only do actual visitors arrive at an abandoned location (404 pages) but any benefits your site has been receiving from links to that page are also lost.
Because 301 redirects tell search engines that the content has been moved permanently, they allow all the benefits (link juice or link metrics) to be passed from the old URL to the new one.
When do you need 301 redirects?
301 redirects are useful when:
• A site update or refresh requires some pages change location.
• Moving from one domain to another.
• Removing a page without losing the link metrics to that page.
• When other websites get the original link to your site wrong