301 redirect

301, 302, 307 and 308

301 and 308 mean moved permanently. 302 and 307 mean moved temporarily. Google treats the permanent ones as a strong signal to index the new URL. Temporary redirects keep the old URL in the index for a while, because you said the move is not final.

308 is the modern twin of 301 that keeps the request method, so a POST stays a POST. For ordinary pages, either works.

When to use one

Changing a slug, merging two pages, moving from http to https, choosing www or non www, or retiring a page whose closest replacement is another page. Redirect each old URL to the most relevant new page, not to the homepage, which Google may treat as a soft 404.

Mistakes to avoid

Chains, where A redirects to B and B to C. Loops. Redirecting to a page that is noindexed or 404s. Linking internally to redirected URLs instead of updating the links. Listing redirected URLs in the sitemap.

Testing redirects

Check each redirect with a tool that shows every hop and status code, not just the final page. Confirm that the old URL answers 301 or 308, that it lands on a 200 page in one step, and that the final page's canonical points at itself. Then update internal links, the sitemap and any ads to the new URL, so the redirect becomes a safety net instead of a daily path.

Example

A launch renamed from /launch/indieai to /launch/indie-ai answers the old URL with a 301 to the new one, so old links and rankings carry over.

Questions people ask

How long should I keep a redirect?

Google suggests at least a year. Keeping it forever is safest when old links still point to the old URL.