How can you successfully migrate to HTTPS without losing your Google rankings?

Why is Google so insistent on HTTPS migrations?

Since Chrome displays warnings on unsecured sites, HTTPS has become a non-negotiable standard. Google has been promoting this adoption for years, but still observes disastrous migrations leading to sharp traffic declines.

The search engine must relearn your entire site during an HTTPS switch. Every HTTP URL technically becomes a new HTTPS URL. If your redirects are shaky or your sitemaps outdated, Googlebot loses its bearings and may temporarily or permanently exclude entire sections of your content from the index.

What happens technically during an HTTPS migration?

Googlebot discovers your new HTTPS URLs in three ways: through 301 redirects from the old HTTP URLs, via your updated sitemap, and through internal and external links pointing to the new versions. If any of these three sources has inconsistencies, crawling becomes chaotic.

The bot will gradually recrawl the entire site in HTTPS. During this transition period, both versions coexist in the index. Google must then decide which version to canonize. If your signals are contradictory (sitemap listing HTTP, missing redirects, canonical tags pointing to HTTP), the engine may get confused.

What are the classic traps that lead to deindexing?

The first trap: leaving chain redirects (HTTP → HTTPS → final version). Googlebot wastes time and may give up before reaching the destination. The second: forgetting to update XML sitemaps, which continue to list HTTP URLs while the whole site redirects to HTTPS.

Another frequent error: configuring HTTPS redirects but forgetting to migrate resources (CSS, JS, images). Content appears in mixed mode, Google detects security issues and may demote the affected pages. Finally, not checking the Search Console HTTPS separately: you miss critical alerts for weeks.

• Permanent 301 redirects mandatory from each HTTP URL to its exact HTTPS equivalent
• XML sitemaps updated with only the final HTTPS URLs
• Internal resources (images, CSS, JS) also migrated to HTTPS to avoid mixed content
• Canonical tags pointing only to the HTTPS versions
• Search Console set up with the new HTTPS property to track errors in real time

Does this statement really reflect the ground reality of migrations?

Yes, but it is deliberately vague about the actual duration of the transition. On the ground, a well-executed HTTPS migration can stabilize traffic in 2-4 weeks. A failed migration can destroy 30 to 60% of traffic for several months, or even permanently if errors are not quickly corrected.

Google also does not specify that the complete recrawl of a large site can take weeks. If your crawl budget is limited, Googlebot will progress slowly, leaving some sections in HTTP in the index for a long time. In this case, forcing a recrawl via the Search Console or increasing the crawl frequency becomes essential.

Are sitemaps really enough to secure the migration?

No, that’s a misleading shortcut. Sitemaps are an indicative signal, not a guarantee of indexing. Google may ignore your sitemaps if the redirects are poorly configured or if the HTTPS content differs significantly from the original HTTP content.

[To be verified] Google claims that sitemaps speed up the discovery of new URLs, but no official documentation quantifies this effect. On larger sites with thousands of pages, I have observed cases where the sitemap alone was insufficient: Googlebot continued to heavily crawl the old HTTP URLs despite a perfectly updated sitemap. 301 redirects remain the priority signal.

What are the cases where this rule does not fully apply?

Sites with a very low crawl budget (low-authority domains, millions of pages) may experience unusually long delays even with a perfect migration. In these cases, Google prioritizes the recrawl of strategic pages and leaves secondary URLs hanging for months.

Another exception: sites with dynamic content or heavy JavaScript. If the HTTPS rendering introduces display differences detected by Googlebot (blocked resources, loading errors), the engine may consider that the HTTP and HTTPS versions are not equivalent and refuse to transfer signals.

What concrete actions should be taken before launching the migration?

Start with a thorough audit of current URLs. Map every HTTP URL that receives organic traffic or has backlinks. Prepare a 1:1 mapping file between old and new URLs. Ensure your server fully supports TLS 1.2 minimum and that your SSL certificate is correctly installed.

Next, test the migration on a complete staging environment. Configure the 301 redirects, check that all resources (images, CSS, JS) are accessible in HTTPS, and simulate Googlebot's behavior with Screaming Frog or Sitebulb. Identify chain redirects, 404 errors, and infinite loops before going live.

How to monitor the migration once it has started?

Add the HTTPS property in Search Console immediately and submit your new sitemaps. Daily monitor the coverage report for indexing errors. Compare the number of indexed URLs in HTTP vs HTTPS: the old domain should gradually empty in favor of the new one.

Also activate organic traffic monitoring segmented by protocol (HTTP vs HTTPS) in Google Analytics. If the HTTP traffic does not decrease quickly, or if the HTTPS traffic does not compensate for the drop, it's a warning sign. Also check the rankings for your strategic keywords: a sharp drop indicates a PageRank transfer issue.

What critical mistakes should absolutely be avoided?

Never leave both versions accessible simultaneously without redirects. Some developers enable HTTPS but leave HTTP active “just in case.” The result: massive duplicate content and total confusion for Googlebot. Always redirect 100% of HTTP traffic to HTTPS right from launch.

Another deadly trap: forgetting to update internal links. If your menus, footer, and content continue to point to HTTP URLs, you force Googlebot to follow millions of unnecessary redirects. This slows down crawling and wastes your crawl budget. Replace all internal links with their HTTPS equivalents before or during the migration.

• Complete audit of HTTP URLs with traffic and backlinks
• SSL certificate installed and verified (minimum TLS 1.2)
• 301 redirects configured URL by URL, tested in staging
• XML sitemaps updated with only HTTPS URLs
• HTTPS property added in Search Console with new sitemaps submitted
• Daily monitoring of the coverage report and organic traffic