What Is a 301 Redirect? How HTTP Defines It and How Google and Bing Treat It

Where the 301 Comes From: RFC 9110

The 301 status code is part of HTTP itself, not a search-engine invention. Its current definition is in RFC 9110, HTTP Semantics, published by the IETF in June 2022, which groups 301 with 302, 307 and 308 as redirects “that indicate this resource might be available at a different URI, as provided by the Location header field”.

The definition in section 15.4.2 reads: “The 301 (Moved Permanently) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs.” Three further points in the standard matter in practice:

• Location header: “The server SHOULD generate a Location header field in the response containing a preferred URI reference for the new permanent URI.” Browsers and crawlers follow that header.
• Method change: “For historical reasons, a user agent MAY change the request method from POST to GET for the subsequent request. If this behavior is undesired, the 308 (Permanent Redirect) status code can be used instead.” For ordinary page moves, which are GET requests, this makes no difference.
• Caching: “A 301 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls”. RFC 9110 says heuristically cacheable responses “can be reused by a cache with heuristic expiration”, so a cache such as a browser may store a 301 and reuse it without asking the server again, unless your cache headers say otherwise. In practice (our inference, not a statement in the standard), a mistaken 301 can therefore persist in some visitors' browsers after you fix it on the server.

A sample response (this is the reply our own server gave on October 8, 2026 to a request for an http:// address):

HTTP/1.1 301 Moved Permanently
Location: https://mediamorpheuspress.com/blog/what-is-a-canonical-url.html

301 vs 302, 307 and 308

RFC 9110 defines four status codes that send a client to another URL; they differ on two questions, permanent or temporary, and whether the client may switch a POST to a GET. Google adds a third difference that matters for search: which URL it shows in results (Redirects and Google Search).

RFC 9110 notes that 308 “is much younger (June 2014) than its sibling codes and thus might not be recognized everywhere.” Google lists 301 and 308 together as permanent server-side redirects, so for search purposes either works; 301 has the longest support across older clients.

How Google Uses a 301 Redirect

Google treats a 301 as a strong canonicalization signal: Googlebot follows the redirect, and the indexing pipeline takes it as a sign that the target URL should be canonical. Google ranks redirects first among the methods for indicating a canonical URL, ahead of rel="canonical" and sitemaps (Consolidate duplicate URLs).

• Server-side is best. Google orders redirect types “by how likely Google is able to interpret correctly”, with server-side redirects first. It interprets an instant meta refresh as permanent and a delayed one as temporary, and says to use JavaScript redirects only if nothing else is possible, because “Google might never see it if rendering of the content failed” (Redirects and Google Search).
• Use it only for real, lasting moves. Google: “Use permanent redirects when you're sure that the redirect won't be reverted.”
• The old URL is not indexed. In Search Console's Page indexing report, a redirecting URL appears as “Page with redirect”: “this URL will not be indexed. The target URL of the redirect might or might not be indexed” (Page indexing report).
• The old address may still appear. Google keeps track of both URLs; the non-canonical one becomes an “alternate name” that “may appear in search results when a user's query hints that they might trust the old URL more”, which Google calls normal after a domain move.
• Hop limit. Google says “By default, Google's crawlers follow up to 10 redirect hops” and that “Googlebot generally follows 10 redirect hops when crawling for general web content” (HTTP status codes and Google). Its site-move guide says Googlebot “can follow up to 10 hops” but advises redirecting “to the final destination directly”, or keeping chains “ideally no more than 3 and fewer than 5” (Site moves with URL changes). Too long a chain, or a loop, shows as “Redirect error”.
• Relevance. Google warns against redirecting many old URLs to “one irrelevant single URL destination, such as the home page”, which “might be treated as a soft 404 error.”
• Duration. For site moves: “Keep the redirects for as long as possible, generally at least 1 year. This timeframe allows Google to transfer all signals to the new URLs.”

Google does not publish how much of a page's ranking signals move through a redirect; its documentation says only that the redirect is a strong canonical signal and that a year allows it to transfer signals. For a full domain move, follow our step-by-step guide to moving a website to a new domain.

How Bing Treats a 301 Redirect

Bing's Webmaster Guidelines give the same instruction as Google in fewer words: when content moves, “Use 301 redirects for permanent URL changes” and “Use 302 redirects only for very short-term changes (less than 2 days)” (Bing Webmaster Guidelines, section 7).

Bing adds “Use redirects instead of canonical tags” and says “Proper redirects preserve visibility, traffic, and grounding continuity.” The same guidelines say they cover “Bing search experiences, Copilot, and grounding API results”. Bing's Block URLs help lists redirecting a URL “if the content has moved and users should be sent to a new location” as one of the permanent steps to complete while a URL is temporarily blocked, and says “Bingbot must be able to crawl the URL and detect the change” (Bing Block URLs help).

Bing's two-day line for 302s is more specific than anything Google states; Google gives no time limit for temporary redirects. A site that uses 302s for permanent moves is out of line with both.

What a 301 Redirect Is Not

A 301 is a server response that says where a resource now lives. It is not an indexing instruction, a canonical tag, a removal method or a promise about rankings, and RFC 9110 says nothing about search engines at all. Treating it as any of those leads to the common mistakes below.

• Not a rel="canonical". A canonical tag leaves both pages reachable; a 301 sends every visitor and crawler to the new URL. Google calls both strong signals; Bing prefers redirects when content moves. See what a canonical URL is.
• Not a removal. If a page is gone with no replacement, return 404 or 410 rather than redirecting to something unrelated. Our guide to removing outdated content from Google covers that route.
• Not a way to hide a page. To keep a live page out of search, use noindex; see noindex vs robots.txt Disallow.
• Not a ranking guarantee. Google says the target “might or might not be indexed, depending on what Google thinks about that target URL.”

How to Set Up a 301 Redirect

Set 301s on the server or in your CMS, which Google says gives the best chance of correct interpretation. Hosted platforms usually have a redirect manager; Google suggests searching your platform's help (for example “blogger redirects”). Examples adapted from Google's documentation:

# Apache (mod_alias)
Redirect permanent "/old" "https://example.com/new"

# NGINX
location = /service {
  return 301 $scheme://example.com/about/service;
}

# PHP
header('HTTP/1.1 301 Moved Permanently');
header('Location: https://www.example.com/newurl');
exit();

Map each old URL to its closest equivalent, redirect straight to the final URL, and update your own internal links and sitemap so they point to the new address rather than through the redirect.

How to Check a 301 Redirect

Check a 301 by requesting the old URL and reading two things in the response: the status line, which should say 301, and the Location header, which should point straight to the final page. A command-line request shows both without a browser cache getting in the way. From a terminal:

curl -sI http://example.com/old-page | grep -iE "^(HTTP|location)"

You should see 301 and a Location pointing straight at a URL that itself returns 200. Check in a private browser window too, because a browser may have cached an earlier redirect.

In Search Console, note two quirks of the URL Inspection tool: the live test “first follows any redirects” and then tests the target “without indicating that there is a redirection”, while the indexed result “will show redirections”. (Google's HTTP status code page, by contrast, says “Google Inspection Tools doesn't follow redirects”; we report both statements as written.) A redirected URL's indexed status shows the old URL, not the target; Google says to click the inspect button in the Page indexing section to see the canonical. Our guide to checking whether a page is indexed walks through the tool.

301 Redirect vs Related Terms

A 301 is one of several ways to tell browsers and search engines about a URL, and each of the alternatives below fits a different situation. The deciding questions are whether the old URL should keep working, whether the change is permanent, and whether the content still exists. Google's and Bing's documentation gives the treatment in each row.

Common Misconceptions About 301 Redirects

Most 301 mistakes come from rules of thumb that the standard and the search engines do not support. Each myth below is set against what RFC 9110, Google or Bing actually says, quoted from the documents listed in the sources, so you can check the wording yourself before changing a redirect plan.

Frequently Asked Questions

Sources and Methodology

This definition is built from RFC 9110 and from Google Search Central, Search Console Help and Bing Webmaster documentation, read on October 8, 2026. Definitions are quoted verbatim. Our one hands-on check was a single HTTP request to an http:// address on our own site on October 8, 2026, which returned 301 with an https:// Location; we did not test how search engines process redirects. Where Google gives no figure (such as how much signal a redirect passes) we say so rather than estimate.

1. official R. Fielding, M. Nottingham and J. Reschke (eds.), IETF, RFC 9110: HTTP Semantics, June 2022. Sections 15.4 (Redirection 3xx), 15.4.2 (301), 15.4.3 (302), 15.4.8 (307), 15.4.9 (308). Read October 8, 2026.
2. official Google Search Central, Redirects and Google Search. Read October 8, 2026.
3. official Google Search Central, Site moves with URL changes. Chains, irrelevant redirects, duration. Read October 8, 2026.
4. official Google Search Central, How to specify a canonical URL with rel="canonical" and other methods. Read October 8, 2026.
5. official Google Search Central, How HTTP status codes, and network and DNS errors affect Google Search. Redirect hop limit. Read October 8, 2026.
6. official Google Search Console Help, Page indexing report. “Page with redirect” and “Redirect error”. Read October 8, 2026.
7. official Google Search Console Help, URL Inspection tool. Read October 8, 2026.
8. official Bing Webmaster Tools Help, Bing Webmaster Guidelines, section 7. Read October 8, 2026.
9. official Bing Webmaster Tools Help, How to Temporarily Block URLs from Bing and Copilot Search Results. Redirects as a permanent fix. Read October 8, 2026.