The entrenched belief in SEO is that using 302 redirects during a site migration causes catastrophic link equity loss. Google has repeatedly stated since 2016 that 301 and 302 redirects pass PageRank equivalently. Both claims miss the actual problem. The real impact of 302s during migration is not equity loss — it is canonical confusion. A 302 tells Google the redirect is temporary, which means Google may continue treating the old URL as canonical instead of transferring canonical status to the new URL. This delays the migration’s indexing completion and can leave the old URLs ranking instead of the new ones for months.
Google confirms equivalent PageRank transfer for 301 and 302 redirects
The evidence on this point is unambiguous. Gary Illyes stated in 2016 that there is no PageRank dilution when using 301, 302, or any 30x redirect. John Mueller confirmed this was not new information but a restatement of existing behavior. The historical claim that 301 redirects caused a 15% PageRank loss — widely cited from a 2010 statement by Matt Cutts — was accurate at the time but has been outdated for over a decade.
The current state: all 3xx redirect types pass full PageRank to the destination URL. A 301 redirect from Page A to Page B transfers the same PageRank as a 302 redirect from Page A to Page B. A direct link from Page A to Page B also transfers the same PageRank. Google has unified the equity transfer behavior across all connection types.
This means the traditional SEO advice to “always use 301 to preserve link juice” is based on an outdated model. The equity transfer is identical regardless of redirect type. The SEO industry has been slow to update this understanding because the original claim was deeply embedded in SEO training materials, and the correction received less attention than the original advice.
However, equity transfer is not the only function of redirects. The distinction between 301 and 302 has shifted from an equity question to a canonical selection question, which is where the real migration impact occurs.
The actual 302 risk: canonical selection delay during migration
Where 302 redirects create genuine problems is in canonical URL selection. When Google encounters a redirect, it uses the redirect type as one signal (among approximately 20, as Gary Illyes has disclosed) for determining which URL should be canonical.
A 301 redirect strongly signals that the source URL has permanently moved to the destination URL. Google interprets this as an instruction to transfer canonical status from the source to the destination. The old URL should be removed from the index and replaced by the new URL. All ranking signals — PageRank, anchor text, indexing history — should be consolidated on the new URL.
A 302 redirect signals that the source URL still exists and the redirect is temporary. Google interprets this as the source URL remaining canonical. The destination URL is an alternate that users should temporarily visit, but the source URL is where rankings should stay. Google may still pass PageRank through the redirect, but canonical status remains with the source URL.
During a site migration — where the intent is to permanently replace old URLs with new URLs — using 302 redirects sends a message that directly contradicts the migration intent. Google sees the 302 and concludes the old URLs are still canonical. The old URLs remain in the index. The new URLs are treated as alternates. Search results continue to show the old URLs, even though they redirect users to the new URLs.
John Mueller has explained the mechanism: Google takes old and new URLs, places them in “a shared cluster,” and then evaluates canonicalization signals including internal links, external links, sitemap presence, and redirect type. A 302 redirect within this cluster points the canonical assessment toward the old URL. A 301 redirect points it toward the new URL.
The observed delay difference: migrations using 301 redirects typically complete canonical transfer within 2-4 weeks for most URLs. Migrations using 302 redirects may take 2-6 months for canonical transfer, because Google must override the redirect’s temporary signal by relying on other canonicalization signals (sitemaps pointing to new URLs, internal links pointing to new URLs) to determine that the move is actually permanent.
Google has stated that if a 302 redirect remains in place long enough, Google may eventually treat it as a 301. Semrush recommends keeping a 302 for no longer than six months. But relying on Google to eventually reclassify a 302 introduces months of unnecessary delay during a migration.
When redirect type matters versus when it genuinely does not
The redirect type distinction is irrelevant in several common scenarios where canonical intent is either unambiguous or not a factor.
A/B testing and temporary experiments. When a page temporarily redirects users to an alternative version for testing purposes, 302 is the correct and safe choice. The original URL is intended to remain canonical, and the redirect will be removed when testing concludes. Using a 301 for a genuinely temporary redirect would cause Google to transfer canonical status prematurely.
Seasonal or promotional redirects. A holiday landing page that temporarily redirects to a standard category page during the off-season should use a 302. The holiday URL is intended to return, and 302 preserves its canonical status for when it is reactivated.
Same-domain URL formatting normalization. When redirecting between URL variants on the same domain (trailing slash vs. no trailing slash, www vs. non-www), the canonical intent is usually clear from other signals (canonical tags, sitemap entries, internal link consistency). The redirect type has minimal impact because Google has multiple other signals confirming which variant is canonical.
Short redirects with strong supporting signals. If a URL restructuring uses 302 redirects but the sitemaps, canonical tags, and internal links all point to the new URLs, the combined weight of non-redirect signals can override the 302’s temporary signal and achieve correct canonical selection. Google’s canonicalization system is multi-signal, and the redirect type is one input among many. When all other signals align with the new URL, the 302’s temporary signal is outvoted.
In specific migration scenarios, the redirect type directly determines how quickly Google completes the canonical transfer.
Domain migrations. Moving from old-domain.com to new-domain.com is the scenario where 301 redirects are most critical. The domain change means there are no shared canonical signals (no shared sitemaps, no shared internal links) to help Google determine intent. The redirect type is the primary signal Google uses to decide whether the move is permanent. A 302 in a domain migration can delay canonical transfer by months, during which the old domain continues to appear in search results.
Protocol migrations (HTTP to HTTPS). Google has confirmed that HTTPS URLs in a canonicalization cluster have a higher chance of becoming canonical. A 301 redirect from HTTP to HTTPS aligns with this preference. A 302 conflicts with it, potentially delaying the HTTPS migration’s completion.
Major URL restructuring with path changes. When URLs change significantly (e.g., /products/item-123 to /shop/category/item-name), the new URL pattern has no historical indexing data. The redirect type is the primary signal telling Google whether the new URL structure is permanent. 301 redirects signal permanence, allowing Google to immediately begin consolidating signals on the new URLs.
Subdomain to subfolder migrations. Moving content from blog.example.com to example.com/blog/ involves a host change that, like a domain migration, has limited shared canonical signals. 301 redirects are essential for timely canonical transfer.
Diagnostic approach for identifying whether 302 usage is causing migration completion delays
If a migration is progressing slowly — old URLs still ranking, new URLs showing as alternates rather than canonicals, Search Console showing the old URL as the “Google-selected canonical” — the redirect type should be investigated.
Step 1: Check redirect types. Using a crawler (Screaming Frog, curl, or browser developer tools), follow the redirect chain from a sample of old URLs. Record the HTTP status code at each hop. If 302 is used anywhere in the chain, it may be suppressing canonical transfer.
Step 2: Verify canonical status in Search Console. Use the URL Inspection tool to check both the old and new URLs. For each pair, note the “Google-selected canonical” URL. If Google selects the old URL as canonical despite the redirect to the new URL, the 302 signal is likely the cause.
Step 3: Check supporting signals. Verify that sitemaps include only new URLs, canonical tags on new pages self-reference the new URL, and internal links point to new URLs rather than old ones. If these signals are misaligned, the 302 is not the sole cause — the supporting signals are also pointing to the old URL.
Step 4: Switch to 301 and monitor. If the redirect type is confirmed as 302 and the migration intent is permanent, change all redirects to 301. Monitor Search Console’s canonical URL reporting over the following 4-6 weeks. The expected recovery pattern: the Google-selected canonical should shift from the old URL to the new URL within 2-4 weeks of the redirect type change.
John Mueller recommends keeping 301 redirects in place for at least one year after a migration to ensure Google’s systems fully consolidate the canonical transfer. The chained redirect crawl equity article explains how redirect chains compound the canonical confusion when mixed redirect types are present.
Does switching a 302 redirect to a 301 after a migration is complete accelerate the canonical transfer?
Changing a 302 to a 301 sends a clearer permanent signal to Google’s canonical resolution system. If Google has been keeping the old URL as canonical due to the temporary 302 signal, switching to 301 prompts a re-evaluation on the next crawl. The canonical transfer typically completes within two to four weeks after the change. For migrations where the 302 has been in place for months, the switch to 301 resolves the canonical ambiguity that the 302 has been maintaining.
Does using a 307 redirect instead of a 302 change how Google processes the redirect during a migration?
A 307 redirect preserves the HTTP method (POST remains POST), while a 302 may convert POST to GET in some browsers. For Googlebot’s crawling purposes, 307 and 302 are functionally equivalent in terms of PageRank passing and canonical signal processing. Both are treated as temporary redirects. The choice between 307 and 302 matters for user-facing application behavior but does not affect SEO outcomes. For site migrations, 301 remains the recommended choice over both 302 and 307.
Does removing 301 redirects after one year of a migration risk losing the transferred link equity?
Google has confirmed that after a sufficient period (typically one year), the old URL’s signals are fully consolidated onto the new URL. Removing the 301 redirect after this period causes the old URL to return a 404, which is acceptable because the equity has already transferred. However, external sites may still link to the old URL. If significant external link volume still points to the old URL, maintaining the 301 indefinitely preserves the ability to capture any remaining referral traffic.
Sources
- Search Engine Land. “Google: There Is No PageRank Dilution When Using 301, 302, or 30x Redirects Anymore.” https://searchengineland.com/google-no-pagerank-dilution-using-301-302-30x-redirects-anymore-254608
- Semrush. “301 vs. 302 Redirect: Which to Choose for SEO and UX.” https://www.semrush.com/blog/301-vs-302-redirect/
- Search Engine Journal. “Google Shares How 301 Redirects Pass PageRank.” https://www.searchenginejournal.com/301-redirect-pagerank/275503/
- Search Engine Roundtable. “Google Puts Redirected URLs into a Cluster for Canonicalization Processing.” https://www.seroundtable.com/google-redirects-cluster-30425.html
- Dub. “301 vs 302 Redirect: Which Is Better for SEO?” https://dub.co/blog/301-vs-302-redirect
