Redirects: Types and Chains

A redirect sends visitors and Google from one URL to another. Redirect types decide two things: which page Google shows in results and whether it treats the redirect as a signal for the canonical page. Often people instead cite percentages of "passed weight" and a "chains no longer than two steps" rule: such figures are not in the documentation. Here is what is actually written.

The basis is Google's page on redirects and the guide to moving a site with URL changes.

Permanent and temporary: what Google shows

To a user the types are indistinguishable. For Google there is a difference: permanent redirects show the new target in results, temporary redirects show the source page.

Use permanent redirects when you are sure the redirect won't be reverted. Use temporary ones when the source URL must stay in results, for example a service is temporarily unavailable and users are sent to a page that explains. In Google's overview of status codes, 301 is a strong signal that the target should be processed and 302 a weak one.

Server-side is the best method

The methods in the documentation's table are ordered by how likely Google is to interpret them correctly, and server-side has the highest chance. The others are fallbacks:

• meta refresh. An instant one (0 seconds) Google treats as permanent, a delayed one as temporary. It goes in the head or in a Refresh header;
• JavaScript location. Use only if you cannot do server-side or meta refresh. More in the lesson on JavaScript and SEO;
• crypto redirects. Do not rely on them if there is any other way.

So where is the "weight loss"?

People often say "301 passes 90-99%, 302 and 307 pass no weight". The site-move guide says otherwise: don't worry about link credit; 301 and other permanent redirects don't cause a loss in PageRank. About "weight" for temporary redirects the page says nothing at all: it describes which page to show and whether the target counts as canonical. So the types cannot be compared by percentages.

Chains

The "no more than two steps" tip and the thesis "every hop loses weight" are not in the documentation either. What is there is different: Googlebot can follow up to 10 hops in a chain, but you are advised to redirect straight to the final destination; if that is impossible, keep the chain short, ideally no more than 3 and fewer than 5. The reason is stated directly: chains add latency for users, and not all user agents support long ones. A real chain and the response codes can be seen in the redirect checker.

Typical situations

• Variants of one address. If the home page is reachable at several addresses, pick one as preferred and redirect the others to it. This is the basis of dealing with duplicates: duplicate content;
• A removed page. Redirect to a suitable replacement. Do not redirect many old URLs to one irrelevant destination such as the home page: that can confuse users and might be treated as a soft 404. The exception is when you consolidated several pages into one, in which case redirecting to it is fine;
• An A/B test. For redirecting to a variation use a 302, not a 301: a temporary redirect says it is in place only while the experiment runs, and the original stays in the index;
• A site move. Keep redirects as long as possible, generally at least 1 year, so Google can transfer all signals, including recrawling links from other sites. For a change of domain or subdomain, submit a Change of Address in Search Console; it is not needed for HTTP to HTTPS, www to non-www, or moving paths within a domain. The full procedure is in the lesson on site migrations.

Redirect and canonical

A redirect is a strong signal, as is rel="canonical". The choice between them is whether the duplicate is needed: if not, use redirects when you want to get rid of existing duplicate pages; if it is, use canonical.

How to check

1. Run important URLs through the redirect checker: the code of each step, the final address and the chain length.
2. Crawl the site with the crawler and find internal links to redirected addresses: replace them with direct ones.
3. Find pages that lead to a 404 instead of a redirect with organic 404s.
4. Check the response code: a permanent move needs 301 or 308, not 302.
5. After a move watch coverage in Search Console; in bulk by URL, use the URL audit.

Checklist

1. A permanent move uses 301 or 308, server-side.
2. A temporary one uses 302 or 307, and the source URL stays in results.
3. There are no chains; the redirect goes straight to the final URL.
4. An old URL redirects to a page that matches in meaning, not to the home page.
5. Internal links and the sitemap point at final URLs.
6. In a move, redirects are kept for at least a year.

Mistakes

• 302 instead of 301 for a move that is permanent.
• Chains and loops of redirects.
• Redirecting all old URLs to the home page.
• A JavaScript redirect where a server-side one is possible.
• Using the expected "loss of weight" as a reason to choose a redirect type.

What comes next

Next on the topic is how redirects combine with canonical, in the lesson on the canonical tag, and a full move in the lesson on site migrations. On URLs see the lesson on URL structure.