What is a redirect?
A redirect is a forwarding address for a web page. When a browser or a crawler requests a URL that has a redirect on it, the server answers with a status code and a new location, and the request continues there without the visitor doing anything. The common kinds are the 301, a permanent move, and the 302, a temporary one, along with their stricter cousins the 308 and 307. There are also redirects set in the page itself, with a meta refresh tag or a line of JavaScript, which are slower and less reliable.
Redirects exist because URLs outlive the pages they pointed at. Products are discontinued, campaigns end, sites are rebuilt, domains change. Every one of those leaves old links in the world, in search results, in emails, in other sites and in bookmarks, and a redirect is what stops those links from dying.
Why it matters
Why redirects matter
Two things ride on them. The first is people: a visitor who follows an old link and hits a dead page leaves, and a brand that has just paid for a campaign does not want its launch URL going nowhere. The second is authority. Links pointing at a page give it ranking strength, and when the page moves, a 301 redirect carries that strength to the new address. Without the redirect, the old URL drops out of the index, the links pointing at it count for nothing, and the new page starts from zero.
At the scale of a site migration or a rebrand, redirects are the difference between keeping the search traffic and losing most of it for months.
In practice
How redirects work in practice
- 01
Pick the right kind. A 301 tells search engines the move is permanent and to transfer everything to the new URL; use it for page moves, merged pages, retired products pointed at their category, and domain changes. A 302 says the move is temporary and the old URL should stay indexed; use it for short promotions, A/B tests and maintenance pages. The redirect is set on the server or in the content management system, and it should point directly at the final destination, one hop, to a page that is genuinely the replacement.
- 02
Then keep the map. Every site should hold a record of its redirects: old URL, new URL, type, date and reason. During a migration the map is built before launch by crawling the old site, matching every URL to its new home and testing the lot. After launch, Search Console and a crawler show what was missed. Old redirects stay in place as long as anything out there still links to the old address, which in practice means years.
Watch out
What people get wrong about redirects
Sending everything to the homepage. A retired product page redirected to the homepage is treated by Google much like a 404, because the destination has nothing to do with the original. Redirect to the closest relevant page, and if there is none, let the page 404 or 410 honestly.
The other mistake is using a 302 for a permanent move because it was the default in the tool. Google now treats long-lived 302s as permanent eventually, but eventually is not a plan. Set the type on purpose.
