Official statement
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Google recommends using 301 redirects even for a temporary site move of six months, instead of 302. This ensures optimal PageRank transfer and avoids ranking losses during the transition. This statement overturns the traditional doctrine that reserved 301 for permanent changes.
What you need to understand
Why does this recommendation challenge the classical theory?
Technical documentation has always clearly distinguished 301 redirects (permanent) from 302 (temporary). The HTTP code 302 explicitly signals to crawlers that the move is provisional and that they should retain the original URL in the index.
Mueller's statement reverses this logic for relocations lasting several months. A six-month move remains technically temporary, but Google now believes that a 301 ensures better algorithmic treatment. The engine prioritizes the fluidity of signal transfer rather than the semantic fidelity of the HTTP code.
What happens technically with a 302 over a long period?
A 302 redirect tells Googlebot to regularly check the source URL. The crawler thus keeps two URLs under active observation: the old one and the new one. This duplication unnecessarily consumes crawl budget.
The PageRank transfer via 302 works, but with greater latency. Google takes longer to consolidate signals on the new URL because the algorithm waits for confirmation of permanence. The result: inefficiency loss for several weeks, or even months, exactly during the period when you need stability.
In which scenarios does this rule really apply?
The six-month threshold mentioned is not trivial. It is the threshold at which Google considers that a relocation deserves permanent treatment, even if you technically plan to revert.
This typically involves redesigns with extended testing phases, migrations to new infrastructures with adjustment periods, or moves to temporary domains during work. In short, all cases where "temporary" actually means several full crawl cycles.
- Optimized PageRank transfer: 301s ensure a swift consolidation of ranking signals on the new URL
- Crawl budget savings: only one URL remains under active observation instead of two in parallel
- Position stability: fewer fluctuations in SERPs during the transition period
- Critical time threshold: beyond a few weeks, a 302 becomes counterproductive even for a temporary move
- Reversal possible: nothing prevents you from removing a 301 later if necessary, contrary to common belief
SEO Expert opinion
Does this recommendation contradict field observations?
No, it rather validates what practitioners have observed for years. A/B tests on temporary migrations consistently show that 301 redirects maintain positions better than 302, even over short periods of 2-3 months.
The important nuance: Google implicitly admits that its treatment of 302s is not as neutral as announced. If a 301 "moves things more efficiently," it's because the 302 indeed introduces algorithmic friction. Not a bug, but a difference in priority in signal processing.
What uncertainties remain in this statement?
Mueller does not specify from which exact duration the switch to 301 becomes necessary. Six months is the given example, but what about a three-month move? One month? [To verify] based on specific use cases.
Another area of ambiguity: what happens if you actually revert after six months of using 301? Will Google quickly reindex the old URL, or will it retain a "memory" of the redirect? Tests show a residual algorithmic memory for several weeks, but no official data quantifies this delay.
In what cases should you still keep a 302?
For very short relocations (less than 3-4 weeks), a 302 makes sense if you absolutely want to avoid any confusion in the index. Typically during quick production tests or emergency switches with a planned return in a few days.
Another edge case: geo-localized or contextual redirects where the source URL remains active for certain users. Here, a 302 clearly signals that the two URLs coexist legitimately depending on the context. But honestly, these situations are more edge cases than typical migrations.
Practical impact and recommendations
What should you concretely modify in your migration strategy?
Stop asking yourself the question "temporary or permanent?" in semantic terms. Instead, ask: how long will this redirect be active? If the answer exceeds one month, default to 301 redirects.
Technically, check your server or CDN configuration. Some CMSs create 302 redirects by default during "temporary" URL changes. You often need to explicitly force the 301 code in the configuration, even if the interface offers a "temporary" mode that seems logical.
How to audit a site that has been using 302s for several months?
Crawl your site with Screaming Frog or Sitebulb in "respect redirects" mode. Identify all redirect chains and their age. If 302 redirects have been active for more than 6-8 weeks, switch them immediately to 301.
Then monitor fluctuations in Search Console for 2-3 weeks. You should observe a consolidation of impressions on the new URLs and a gradual disappearance of the old ones from the coverage reports. If it stagnates, it means the crawl budget isn’t keeping up and you may need to force a recrawl via the Indexing API.
What critical mistakes to avoid during implementation?
Never mix 301 and 302 within the same migration logic. Either you commit to a permanent transfer for the entire duration, or you stick to ultra-short-term 302s. Hybrid configurations create contradictory signals that further delay processing.
Another classic pitfall: forgetting to update the XML sitemap. If your redirects point to new URLs but the sitemap still lists the old ones, Google will prioritize crawling the outdated URLs. The sitemap must reflect the final target state, not the source state.
- Audit all redirects active for more than 4 weeks and check their HTTP code
- Explicitly configure 301s in the server/CDN for any planned relocation beyond one month
- Update the XML sitemap with the final URLs, not the redirected sources
- Monitor Search Console to verify consolidation of impressions on the new URLs
- Avoid redirect chains: point directly to the final URL in a single hop
- Document the expected duration of each redirect to reevaluate the strategy if the timeline changes
❓ Frequently Asked Questions
Une redirection 301 peut-elle être annulée si je reviens finalement à l'URL d'origine ?
Combien de temps Google met-il à transférer le PageRank via une 301 ?
Les 302 font-elles perdre du PageRank contrairement aux 301 ?
Faut-il utiliser des 301 même pour un test A/B de quelques semaines ?
Que se passe-t-il si je laisse des 302 actives pendant plus d'un an ?
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