301 Redirect
A 301 redirect is a server response that permanently sends both users and search engines from an old URL to a new one. It passes ranking signals to the destination and is the standard way to move a page for good.
A 301 redirect is your server's way of saying this page has moved permanently, go here instead. When a browser or a crawler requests the old URL, the server responds with a 301 status code and the address of the new location, and the request is forwarded automatically. The user lands on the new page and usually never notices anything happened.
For SEO, the 301 is the workhorse. It is the correct tool whenever you permanently retire a URL: changing a slug, merging two pages, moving to HTTPS, switching domains, or consolidating duplicate content. The key property is that a 301 passes along the ranking signals the old URL had built up, so you keep most of the value you earned instead of starting from zero.
Use a 301 when the move is permanent. It tells search engines to transfer the old page's ranking signals to the new URL and to update the index accordingly.
301 versus 302 in one breath
The difference is permanence. A 301 means permanent, so the engine eventually replaces the old URL with the new one in its index and moves the signals over. A 302 means temporary, so the engine keeps the old URL as the canonical and treats the move as something you will undo. Using a 302 when you meant 301 is a classic way to leak ranking strength and confuse indexing.
How to set one up
# Apache .htaccess, redirect a single URL
Redirect 301 /old-page/ https://www.yoursite.com/new-page/
# Nginx, redirect a single URL
location = /old-page/ {
return 301 https://www.yoursite.com/new-page/;
}- 1Map every old URL to its single best matching new URL before you flip anything.
- 2Redirect to the closest relevant page, not lazily to the homepage.
- 3Implement the redirects as true server-side 301s, not JavaScript or meta refresh hacks.
- 4Test a sample of redirects to confirm they return a 301 and land on a 200 page.
- 5Update your internal links and sitemap to point straight at the new URLs.
warningWATCH OUT
Avoid redirect chains, where one URL redirects to a second that redirects to a third. Each hop wastes crawl resources and dilutes signals, and long chains can stop being followed entirely. Always redirect the original URL straight to the final destination in a single step.
targetMigration rule
During a site migration, redirecting everything to the homepage is the cardinal sin. Google often treats homepage-dumped redirects as soft 404s and the ranking value evaporates. Map old pages to the most relevant new page one at a time, even when it is tedious.
Keep redirects live
Do not remove 301 redirects a month after a migration. Keep them in place long term. Crawlers and old backlinks keep hitting the old URLs for years, and pulling the redirects too early throws away the equity you preserved.
One thing to set expectations on: a 301 is not instant in the index. After you put redirects live, search engines still need to recrawl the old URLs, see the 301, and process the move. That can take days or weeks depending on how often those pages get crawled. During that window you may see the old and new URLs both appearing, or some ranking wobble. That is normal. As long as the redirects are correct and stay in place, the engine works through them and consolidates onto the new URLs.
The 301 is the single most important tool in any URL change, and getting the mapping right is most of the battle. For the complete process, including how to plan and QA a move without losing traffic, see my site migrations guide.
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