Redirect (301 or 302)

A redirect automatically forwards both users and crawlers from one URL to another. Redirects come into play when a page changes address, when content is removed, or when an entire site moves to a new domain. The two that matter most are the 301, which is permanent, and the 302, which is temporary, and the difference has direct consequences for your SEO.

A 301 tells search engines the page has moved for good. Google therefore moves the page's signals to the new URL, including the value of the backlinks pointing at the old address, and swaps it out in the index. That makes 301 the standard choice for new URL structures, domain changes and retired pages. Without it, old links and bookmarks land on a 404 page and accumulated authority is lost.

A 302 says the opposite: the old URL is coming back, so keep it in the index. It belongs on campaign pages, A/B tests and pages that are down for a short while. Used where the move is in fact permanent, it sends Google mixed signals and delays the change in the index.

In practice the trouble appears in chains, where one redirect leads to the next, and in loops, where two URLs point at each other. Every extra hop costs response time and crawl resources, and crawlers follow only a limited number of hops before giving up. Clearing chains and loops is standing maintenance, and the guide to site health and redirects has it.