How Redirects Affect SEO Rankings

Redirects are one of the most powerful tools in SEO. They are also one of the most misunderstood. A single redirect can preserve years of accumulated link equity, or it can silently drain it. The difference depends on which type you use, how you implement it, and whether you avoid the handful of mistakes that trip up even experienced site owners.

This article covers exactly how redirects affect search rankings, what Google has said about them over the years, and how to use them without losing traffic. For a broader overview of redirect mechanics, see the HTTP Redirect Guide.

How PageRank Passes Through Redirects

PageRank is Google's original algorithm for measuring the importance of a page based on the links pointing to it. When you redirect one URL to another, the question is simple: does the link equity from the old URL transfer to the new one?

The answer depends on the redirect type.

301 Redirects: Full PageRank Transfer

A 301 redirect tells search engines that a page has permanently moved. Google has confirmed that 301 redirects pass full PageRank to the destination URL. This was not always the case. For years, the SEO community operated under the assumption that 301s lost roughly 15% of PageRank in the transfer. Google's Gary Illyes put that myth to rest in 2016 when he confirmed on Twitter/X that "30x redirects don't lose PageRank anymore."

This means a properly implemented 301 redirect should preserve all the ranking power of the original URL. If your old page had strong backlinks, those links will continue to benefit the new URL.

302 Redirects: A Different Story

A 302 redirect tells search engines the move is temporary. In theory, search engines should keep the old URL in their index and not transfer ranking signals to the new one. In practice, Google's behavior is more nuanced. If Google detects that a 302 has been in place for a long time, it may eventually treat it like a 301 and transfer some equity. But this process is slow, unpredictable, and not something you should rely on.

The practical advice: if you want link equity to transfer, use a 301. A 302 used where a 301 belongs can leave your ranking signals stuck on a URL that no longer serves content.

307 and 308 Redirects

307 and 308 redirects are the method-preserving equivalents of 302 and 301 respectively. From an SEO perspective, Google treats a 308 the same as a 301 and a 307 the same as a 302. The distinction between them matters for API endpoints and form submissions, not for search rankings.

How Redirects Affect Indexing

When Google encounters a redirect, it has to decide which URL to keep in its index: the source, the destination, or both.

301s Signal Canonicalization

A 301 is one of the strongest canonicalization signals you can send. When Googlebot follows a 301, it understands that the old URL should be replaced by the new one in the index. Over time (usually days to weeks), the old URL drops out of search results and the new URL takes its place. Any ranking signals associated with the old URL are consolidated onto the new one.

302s Keep the Old URL Indexed

A 302 tells Google the move is temporary, so Google typically keeps the old URL in its index. This is the correct behavior if you genuinely plan to bring the old URL back. But if the move is actually permanent and you used a 302 by mistake, you end up with the old URL sitting in the index pointing nowhere useful while the new URL struggles to accumulate ranking signals.

This is one of the most common SEO mistakes on the web. Many web frameworks default to 302 redirects, and developers who do not explicitly check their status codes end up with temporary redirects on permanent moves.

Crawl Budget and Redirects

Crawl budget is the number of pages Googlebot will crawl on your site within a given time period. For most small to mid-sized sites, crawl budget is not a practical concern. But for large sites with thousands or millions of pages, redirects can eat into that budget.

Every redirect requires Googlebot to make an additional request. If Googlebot hits URL A, gets redirected to URL B, and then gets redirected to URL C, that is three requests to reach one page. Multiply that by thousands of redirected URLs and you start consuming crawl budget on pages that do not even exist anymore.

Google has said that a single redirect (one hop) is fine and does not cause problems. The issues start when redirects chain together or when large portions of a site are redirected without cleanup.

How to Protect Your Crawl Budget

Keep redirect chains to a single hop wherever possible. After a site migration, update internal links to point directly to the new URLs rather than relying on redirects. Remove outdated redirect rules once Google has indexed the new URLs. For more on detecting and fixing chains, see Redirect Chains Explained.

Redirect Chains and Equity Dilution

A redirect chain is a sequence of multiple redirects between the original URL and the final destination. For example:

Page A --> Page B --> Page C --> Page D

Each hop in a redirect chain introduces a small risk. While Google has stated that PageRank passes through redirect chains, the practical reality is messier. Chains increase the chance of something breaking: a single misconfigured hop can cut off equity transfer entirely. They also slow down crawling and increase the time it takes for Google to discover and index the final destination.

Chains commonly form during site migrations when old redirects are not updated to point to the current URL. If you migrated from domain-a.com to domain-b.com two years ago, and then migrated to domain-c.com last year, you may have a chain: domain-a.com redirects to domain-b.com, which redirects to domain-c.com. The fix is to update the first redirect so domain-a.com points directly to domain-c.com.

Google has said it will follow up to 10 hops in a redirect chain before giving up. But just because Google can follow long chains does not mean you should create them. Every unnecessary hop is a risk. You can detect chains on your site using Redirect Tracer or by following our guide on how to find redirect chains.

301 vs 302 for SEO: The Practical Decision

The choice between 301 and 302 comes down to one question: is this move permanent?

If the answer is yes, use a 301. This includes domain migrations, URL restructuring, HTTPS upgrades, and any situation where the old URL will not be used again. The 301 sends an unambiguous signal to search engines, transfers full link equity, and gets the new URL indexed as quickly as possible.

If the answer is genuinely no (A/B tests, maintenance pages, seasonal promotions), use a 302. The old URL keeps its index position and ranking signals, ready for when you bring it back.

If you are not sure, default to 301. The cost of a wrong 302 (delayed equity transfer, slower indexing) is almost always higher than the cost of a wrong 301 (aggressive browser caching that can be cleared). For the full comparison, see 301 vs 302 Redirects.

Common SEO Redirect Mistakes

Using 302 for Permanent Moves

This is the single most common redirect mistake in SEO. Many servers, frameworks, and CDNs default to 302. If you set up a redirect and do not explicitly specify 301, check the status code. A tool like curl or Redirect Tracer will show you exactly what code the server returns.

Redirecting to Irrelevant Pages

A redirect should send users (and search engines) to a page that serves the same intent as the original. Redirecting a product page to the homepage is not a meaningful redirect. Google treats redirects to irrelevant destinations similarly to soft 404s, which means you lose the ranking benefit. Always redirect to the most relevant equivalent page.

Not Updating Internal Links After Migration

After a site migration, many teams set up redirects and call it done. But every internal link still pointing to the old URL forces both users and search engines through an unnecessary redirect. Update your internal links to point directly to the new URLs. This removes unnecessary hops, speeds up page loads, and preserves crawl budget.

Creating Redirect Loops

A redirect loop occurs when URL A redirects to URL B, and URL B redirects back to URL A. The browser gets stuck in an infinite cycle and eventually gives up with an error. Search engines will also fail to crawl either page. Loops are easy to create accidentally when multiple redirect rules conflict with each other. For troubleshooting, see How to Fix ERR_TOO_MANY_REDIRECTS.

Letting Chains Grow Unchecked

Every site migration adds a layer of redirects. Without cleanup, chains grow longer over time. Audit your redirects periodically and flatten chains by pointing all redirects directly to the current final destination.

What Google Has Said Over the Years

Google's official guidance on redirects and SEO has evolved significantly.

Before 2016: The SEO community widely believed that 301 redirects lost approximately 15% of PageRank. This belief was based on a 2010 statement by Matt Cutts, Google's former head of webspam, who suggested there was some PageRank loss through redirects. This led many site owners to avoid redirects whenever possible, even when they were the correct technical solution.

2016: Gary Illyes, a Google Search Analyst, confirmed on Twitter/X that "30x redirects don't lose PageRank anymore." This was a significant shift. It meant that properly implemented redirects should not negatively affect your rankings. The announcement did not specify when the change took effect, but it fundamentally changed best practices for site migrations.

2019 and beyond: Google Search Central documentation now clearly states that 301 redirects pass ranking signals. John Mueller has repeatedly confirmed in Google Search Central office hours that redirects are a normal part of the web and that Google handles them well. The current guidance is straightforward: use the right redirect type for your situation, keep chains short, and redirect to relevant content.

The full Google Search Central documentation on redirects is available at developers.google.com.

Monitoring Your Redirects for SEO

Setting up redirects correctly is only half the job. You also need to verify they are working and monitor them over time.

After implementing redirects, check the status codes using curl, browser developer tools, or a redirect tracing tool. Verify that 301s return 301 (not 302), that the destination URLs are correct, and that there are no unintended chains or loops.

For ongoing monitoring, periodically crawl your site to check for new chains, broken redirects, or status code changes. Site migrations are particularly risky periods. Even a well-planned migration can introduce unexpected redirect issues when multiple teams are updating DNS records, server configs, and CDN rules simultaneously.

If you suspect redirects are affecting your search performance, check Google Search Console for coverage issues. The "Page indexing" report will show URLs that Google could not crawl due to redirect errors, and the "Links" report can help you verify that link equity is flowing to the right pages.

References

1. Google, "Redirects and Google Search," Google Search Central, 2024. https://developers.google.com/search/docs/crawling-indexing/301-redirects
2. Gary Illyes, Google, "30x redirects don't lose PageRank anymore," Twitter/X, July 2016.
3. IETF, "RFC 9110 - HTTP Semantics, Section 15.4: Redirection 3xx," June 2022. https://httpwg.org/specs/rfc9110.html#status.3xx