What is a 301 redirect?
A 301 redirect is a server response that says a page has "moved permanently" to a new URL. Browsers follow it automatically, and so do search engines. A visitor who opens the old address lands on the new one.
Google treats it as more than a forward. It says that with a permanent redirect, "the indexing pipeline uses the redirect as a signal that the redirect target should be canonical."
How is a 301 different from a 302?
The number tells search engines how long the move lasts:
| Type | Codes | What Google shows in search results |
|---|---|---|
| Permanent | 301, 308 | "the new redirect target" |
| Temporary | 302, 303, 307 | "the source page" |
Google says to use permanent redirects "when you're sure that the redirect won't be reverted."
When does a moving company need one?
Whenever a page's address changes for good: a redesign with new URLs, a service page that's been merged into another, or a move to a new domain. Each old URL should redirect straight to its closest new page, not through a chain of redirects. See how to redesign a website without losing rankings.
Redirects are also one of the ways Google picks a page's preferred URL. See what is a canonical tag.