“301” is an HTTP status code for a permanent redirect from one URL to another. 301 redirects typically indicate a page has been moved, deleted, or updated — sending visitors and search bots to the new URL.

301 redirects are essential for site rebrands and restructures to preserve traffic and external backlinks.

Despite their importance, 301s redirects can do more harm than good if improperly executed.

Link Equity

Google’s founding premise for organic rankings was based on the number and quality of links to a page — i.e., link equity. But what happens to rankings when the page is 301-redirected to another?

Ten years ago, Google’s Matt Cutts said a 301 redirect reduces a small amount of link equity.

Then, in 2016, Moz published a case study addressing how much is lost. Per the study, a 301 redirect causes a 15% drop in organic traffic. A chain of redirects — page A redirects to page B which redirects to page C — produces a 15% reduction for each one.

The study redirected a page from /barstool.html to /bar-tool.html to /29-inch-bar-stool.html. The result was a consistent loss of organic traffic.

Moreover, there was no evidence of recovery months afterward.

In 2022, Google’s John Mueller more or less confirmed that 301 redirects can reduce link equity, stating it’s best to update links rather than redirect them.

1:1 Replacements

Mueller tweeted in 2017 that redirects should be used for “1:1 replacement URLs” — presumably redesigns and rebrands. A 301 redirect to an unrelated page could result in Google passing no link equity, such as a status code “404,” signaling the page no longer exists.

Hence, don’t redirect the page of an expired product even if the new product is similar. Let the expired product page say “Sold out” and include a link on that page for the new item. Yes, it’s an extra step for shoppers, but it prevents confusion from landing on an unexpected page. And it preserves at least a bit of link equity.

Dos and Don’ts

Here’s how I’ve come to use 301 redirects after a decade of SEO.

• Avoid URL changes if possible. I’ve never seen a redirected page entirely retain its original ranking.

• Avoid 301s for internal links. When changing a site’s domain name or structure, change all internal links to the new URLs. Never redirect them.

• Update a page before redirecting it. If you need to redirect a page, update its content to match the new page and let Google index the original URL. Then, redirect it. That will enable Google to know both pages are identical and pass link equity through the redirect. Likewise, for a new domain name, update the content of the old site to match the new one. Let Google crawl the old site before redirecting it. Help Google understand the redirects are for exact replacements.

• Beware of purchasing a site for the backlinks. Think twice before buying a site to redirect its link equity. The redirects will not likely work unless the pages are nearly identical.

Implementing 301s

Setting up a 301 redirect is deceptively easy. Plugins for WordPress and apps for Shopify appear to do the job without a developer. But those shortcuts are not failsafe.

Inadvertently omitting links — internal or external — can cause serious ranking drops. Never implement 301s without a comprehensive strategy involving content updates, maps of old and new URLs, and thorough checking afterward.