How it differs from 302
A 302 redirect is marked as temporary: a search engine may keep the original URL in its index, expecting it to return, and does not transfer signals to the new address in full. A 301 is treated as a final decision – over time, the old page is removed from the index, and the new one begins appearing in search results.
At the same time, since 2016 Google has stated directly: changing the redirect type itself does not “eat up” a page’s authority – losses usually occur because of long redirect chains or a mismatch between the content of the old and new pages, not because of the response code itself.
What this means in practice
301 redirects are needed when changing domains, restructuring URLs, or merging duplicate pages. For the authority to pass to the new address almost completely, it is important to redirect to a page with similar content in a single step, without long chains like “page A to B to C”.
Who it is critical for
It is essential for any website that changes its URL structure or moves to a new domain. On website builders, redirects are configured through the control panel rather than a configuration file, so this step is often forgotten when reorganizing sections.