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Official statement

Switching to HTTPS should not cause a noticeable loss of traffic. If a long-term decline is observed after a HTTPS migration, it may indicate an issue that needs to be checked.
44:23
🎥 Source video

Extracted from a Google Search Central video

⏱ 1h00 💬 EN 📅 22/09/2014 ✂ 9 statements
Watch on YouTube (44:23) →
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Official statement from (11 years ago)
TL;DR

Google states that a properly executed HTTPS migration should not result in a noticeable loss of traffic. If a lasting decline is observed, it indicates a specific technical issue during the migration. The key is to quickly identify these errors to correct the course before the impact becomes irreversible.

What you need to understand

Why does Google insist on the absence of traffic loss?

Since the introduction of HTTPS as a ranking signal, Google has consistently delivered the same message: a migration should not penalize a site that follows best practices. This position aims to alleviate the psychological barriers of website owners who are still hesitant to secure their content for fear of a negative impact.

The search engine considers the move to the secure protocol as algorithmically neutral, provided that the 301 redirects, URL consistency, and the sitemap XML file update are flawless. A temporary drop lasting a few days may occur during the reindexing phase, but it should never become permanent.

What distinguishes a normal drop from a real issue?

Minor fluctuations over 48 to 72 hours after migration are expected: Googlebot needs to recrawl the pages, consolidate signals, and transfer the PageRank from the old URLs to the new ones. This is an inevitable technical transition phase.

However, if the organic traffic curve remains below the pre-migration level beyond two weeks, it signals a specific technical malfunction. Classic causes include chain redirects, misconfigured SSL certificates, canonical tags pointing to the old HTTP URLs, or a robots.txt file blocking access to critical resources.

How does Google detect HTTPS migration errors?

The engine relies on several indicators to assess the quality of a migration. It first checks that all old HTTP URLs point to a clean 301 response code, without going through temporary 302 redirects that would dilute the PageRank transfer.

Next, Search Console reports certificate errors, mixed content (HTTP resources loaded on an HTTPS page), and redirection chain issues. These alerts allow for quick diagnosis of anomalies and necessary corrections before traffic collapses persistently.

  • A well-executed HTTPS migration generates no sustained loss of organic traffic
  • Temporary fluctuations over 48-72 hours are normal during the reindexing phase
  • A prolonged drop beyond two weeks reveals a technical problem that needs to be identified
  • The 301 redirects, URL consistency, and the sitemap update are the three pillars of a successful migration
  • Search Console remains the reference tool for detecting configuration errors in SSL

SEO Expert opinion

Is this statement consistent with field observations?

Yes, but with a significant caveat: the definition of 'properly executed' remains vague for many practitioners. On paper, a HTTPS migration boils down to three simple technical steps. In reality, each site has its own architectural specifics that complicate matters: thousands of external backlinks pointing to HTTP URLs without redirection, misconfigured subdomains, CDNs with outdated cache rules.

Sites that lost traffic after moving to HTTPS generally made one or more errors that are invisible at first glance: internal redirects that create three-level chains, outdated hreflang tags, or orphan pages left in HTTP. Google doesn't forgive these oversights, even if its official messaging suggests that everything should 'go well'.

What nuances should be added to Google's position?

First point: the notion of 'notable loss' is subjective. A 5% drop in organic traffic may go unnoticed on a large e-commerce site, but it can spell disaster for a blog monetized through advertising. Google provides no quantified threshold to define what is 'notable' or not. [To be verified]: this imprecision leaves much room for interpretation.

Second nuance: timing. Google refers to 'long-term decline', but does not specify if this means one month, three months, or six months. However, some sites took several months to regain their initial traffic level after a HTTPS migration, even without major technical errors. The trust transfer between the old and new version of a site can take time, especially for competitive queries where every signal counts.

In which cases does this rule not apply?

Sites with a history of manual or algorithmic penalties constitute a special case. If a site was already under scrutiny for spam or duplicate content, switching to HTTPS may serve as an excuse for Google to reevaluate the entire domain. The result can then be a drop in visibility that has nothing to do with the HTTPS protocol itself.

Another exception: sites migrating to HTTPS while simultaneously changing their URL structure, CMS, or content hierarchy. In this case, it becomes impossible to separate the impact of HTTPS from other modifications. Google actually recommends decoupling these operations to isolate the effects of each, but many redesigns are done in one go for budgetary or scheduling reasons.

Practical impact and recommendations

What should be checked immediately after a HTTPS migration?

The first action is to audit all 301 redirects to ensure they point directly to the new HTTPS URLs without going through 302 or intermediate chains. A tool like Screaming Frog can crawl the entire site and identify chain redirects that dilute PageRank.

Next, check that the SSL certificate covers all the used subdomains (www, blog, shop, etc.) and that no external resource (images, scripts, CSS) is loaded over HTTP on HTTPS pages. This mixed content generates security alerts in browsers and can degrade Google's trust in the domain.

How can you avoid classic configuration errors?

The most common mistake is leaving canonical tags pointing to the old HTTP URLs instead of updating them to HTTPS. This inconsistency sends a contradictory signal to Google: the redirects say 'go to HTTPS', but the canonicals say 'the reference version is HTTP'. The engine may then hesitate and index the wrong version.

Another pitfall: forgetting to update the sitemap XML file and hreflang declarations. If the sitemap continues to list HTTP URLs, Google will crawl them, encounter 301s, and lose valuable crawl time. On large sites, this can delay full reindexing by several weeks.

What follow-up strategy to adopt after the migration?

Set up a daily monitoring of organic traffic by segment (categories, page types, main queries) to detect any anomalies before they amplify. Tools like Google Analytics and Search Console should be checked daily for the first two weeks.

Configure automatic alerts on critical metrics: more than 10% drop in traffic in one day, increases in 4xx or 5xx errors, or a sudden drop in the number of indexed pages. These indicators allow for immediate response and correction before the impact becomes irreversible.

  • Audit all 301 redirects to eliminate chains and unnecessary 302s
  • Ensure the SSL certificate covers all subdomains used on the site
  • Update canonical tags, the XML sitemap, and hreflang declarations
  • Check for the absence of mixed content (HTTP resources on HTTPS pages)
  • Implement daily monitoring of organic traffic during the first 15 days
  • Set up automatic alerts on critical metrics (traffic, errors, indexing)
Migrating to HTTPS is a technical operation that allows for no approximations. Post-migration checks must be thorough and methodical to avoid any lasting traffic loss. If your infrastructure is complex or if you lack internal resources to supervise every detail, partnering with a specialized SEO agency can secure the transition and ensure optimal PageRank transfer.

❓ Frequently Asked Questions

Combien de temps dure la phase de transition après une migration HTTPS ?
La période de réindexation complète prend généralement entre 48 et 72 heures pour les sites de taille moyenne. Les gros sites avec plusieurs centaines de milliers de pages peuvent nécessiter jusqu'à deux semaines pour que Google recrawle l'intégralité du contenu et consolide les signaux.
Une baisse de 5% du trafic après migration HTTPS est-elle normale ?
Non, même une baisse de 5% signale un problème technique à identifier. Une migration correctement exécutée ne devrait provoquer aucune perte durable de trafic organique, uniquement des fluctuations légères pendant les premiers jours.
Faut-il mettre à jour manuellement tous les backlinks externes après une migration HTTPS ?
Ce n'est pas obligatoire techniquement puisque les redirections 301 transfèrent le PageRank, mais contacter les sites référents pour qu'ils mettent à jour leurs liens vers les URLs HTTPS améliore la vitesse de crawl et évite les détours de redirection.
Les certificats SSL gratuits de Let's Encrypt sont-ils suffisants pour le SEO ?
Oui, Google ne fait aucune différence entre un certificat gratuit Let's Encrypt et un certificat payant EV. Seule la validité technique du certificat compte pour le moteur de recherche.
Peut-on revenir en HTTP si la migration HTTPS pose problème ?
Techniquement oui, mais c'est fortement déconseillé. Un retour en arrière créerait une nouvelle vague de redirections et de confusion pour Google, aggravant potentiellement les problèmes au lieu de les résoudre. Mieux vaut identifier et corriger les erreurs de migration.
🏷 Related Topics
HTTPS & Security AI & SEO Pagination & Structure Redirects

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