301 Redirects: Are They Truly Permanent?


In the world of SEO, understanding how 301 redirects work is crucial. A common belief has been that when a redirect is removed, the “signals” it used to pass would no longer be transferred. However, a recent assertion by Google’s Gary Illyes in 2021 might challenge this long-held assumption. Illyes suggested that redirect signals consolidate permanently to the new location after one year, meaning that even if the redirect is removed, the original URL’s signals are permanently passed to the new one. If the original page is restored, it must build brand-new signals independently​.​

I. A Test in SEO Redirect Theory

To test the validity of this claim, an experiment was conducted in which redirects were removed from specific pages on the Ahrefs blog. The pages chosen had older posts redirected to them, with the assumption being that their substantial links and referring domains would be affected noticeably if the redirects were removed​​.

Following the removal of the redirects, a clear drop in referring domains was observed. Interestingly, this did not translate into a significant drop in traffic to these posts. While one post experienced increased traffic, two remained relatively flat, and only one saw a decrease. It’s important to note that the decrease had started a few days before the removal of the redirects, so it’s unclear whether the redirect removal directly caused this drop​​.

Despite these results, it’s impossible to definitively conclude that permanent redirects continue to pass value even after a year. This concept contradicts the conventional understanding of how SEOs thought redirects worked and requires more rigorous testing for verification​​.

II. The SEO Implications

If the theory holds, the impact on the SEO industry could be enormous. For instance, SEO professionals might need to reconsider their strategies for handling 404 pages. It’s common practice to redirect these pages, especially when they have links pointing to them. If the value of redirects is permanent after a year, SEOs may need to differentiate between redirects that have been in place for over a year and those that have not. The former might no longer require attention, which could streamline the workload for SEO professionals​​.

Additionally, the value of buying domains with established links could change drastically. SEOs often purchase such domains when planning to launch a new website or redirect to their current site, hoping the pre-existing links will boost their rankings. However, if the value of these links is permanently transferred after a year of redirection, the worth of these domains might drop significantly​.

III. A Potential Impact on SEO Tools

SEO tools like Ahrefs could also be affected if redirects do permanently pass value. When redirects are involved, these tools must modify how they display links and domains. This could lead to questions from users when redirects are removed, as the system would still show these links despite the absence of redirects​​.


While the findings are still inconclusive, this exploration opens a new perspective on how permanent redirects function in SEO. There hasn’t been a noticeable change in the SEO industry or SEO recommendations since Illyes’s assertion. Still, it could be because the idea is too new or fundamentally contradicts established beliefs. More tests are needed before we can conclude whether permanent redirects indeed permanently pass signals​1​. As we continue to explore and understand the intricacies of SEO, it’s crucial to stay open-minded and ready to challenge long-standing assumptions.

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