301 Redirect

A 301 is an HTTP status code meaning "this page has moved permanently". When a browser or crawler requests the old URL, the server sends them to the new one. Because it signals permanence, search engines transfer the old page’s ranking signals to the destination and eventually swap the new URL into their index.

Use a 301 whenever a URL changes for good — a migration, a restructured path, merging two pages, or consolidating duplicates. Always redirect to the closest equivalent page, not blanket-redirect everything to the homepage (Google treats homepage catch-alls as soft 404s). Keep a redirect map for every migration and test it before and after launch; broken or missing 301s are the number-one cause of traffic loss in site moves.

Senior practitioners treat redirects as authority plumbing. Avoid chains (A→B→C) — each hop dilutes signals and slows crawlers; point every old URL directly at the final destination. On large migrations, model the redirect map against the highest-traffic and highest-equity URLs first, monitor crawl and index swaps in Search Console, and keep 301s in place for at least a year since consolidation is not instant.