Why should you choose a 301 over a 307 when migrating to HTTPS?

What is the real difference between a 307 and a 301 for Googlebot?

The 307 (Temporary Redirect) code tells the client that the requested resource has temporarily changed address. Modern browsers interpret this and automatically redirect the user. But here’s the catch: Googlebot does not follow this browser logic during crawling.

The 301 (Moved Permanently) code signals a permanent change of URL. This is the signal that Googlebot expects to understand that it must transfer ranking signals (PageRank, links, history) to the new HTTPS URL. Without a 301 on the server side, you lose this SEO juice transfer.

Why do browsers and Googlebot react differently?

Modern browsers incorporate HTTPS security mechanisms that automatically trigger 307 redirects to protect the user. It’s a transparent security layer for user experience, but invisible to the search engine.

Googlebot, on the other hand, analyzes the HTTP headers returned by the server. It does not simulate a complete browser with all its security layers. It reads the status code, period. If your server returns a 307, Googlebot sees it as temporary and transfers nothing. If it’s a 301, it consolidates the signals to the new URL.

What happens if you misconfigure your redirects?

Without a server-side 301 redirect, your HTTPS pages are treated as distinct URLs from your old HTTP ones. The result: dilution of PageRank, potential content duplication, loss of positions in the SERPs. You start from scratch even though you had a history.

Another pitfall: if you rely solely on the browser’s automatic redirect (307), you create a user experience that is correct but a SEO disaster. Users can see your HTTPS, but Google continues to crawl and index your old HTTP URLs with now inaccessible or duplicated content.

• The 307 is managed by the browser, not by Googlebot during crawling
• The 301 on the server side is mandatory for transferring SEO signals
• A HTTPS migration without a 301 amounts to creating a new site in Google's eyes
• 301 redirects must point URL by URL (no global redirect to the homepage)
• Check your redirects with a raw HTTP header analysis tool, not just in a browser

Is this distinction consistent with field observations?

Absolutely. Failed HTTPS migrations we analyze in audits consistently reveal the same pattern: no 301 redirect configured on the server side, only HSTS activated or automatic browser redirect. The client sees their site in HTTPS, thinks everything is fine, and three weeks later traffic drops by 40%.

What John Mueller doesn't make clear here (and would have been useful): the delay in consolidating signals. Even with perfect 301s, Google takes several weeks to fully transfer PageRank. During this transition period, you may observe fluctuations in positions. This is normal, but distressing for the client new to SEO.

What specific cases does this rule not cover?

First nuance: sites with millions of pages. Configuring 301 redirects URL by URL can become a technical nightmare. Some CMS handle this automatically, others require complex .htaccess or nginx rules. In these cases, test first on a subset of critical pages before rolling out comprehensively.

Second blind spot: cascading redirects. If you already have 301s on certain URLs (following a redesign), and then you add another layer of HTTP to HTTPS 301, you create chains. Google follows up to 5 redirects, but each jump dilutes the PageRank transmitted. Ideally, update your old redirects to point directly to the final HTTPS version. [To be verified]: the exact impact of each link on PageRank transfer remains vague in official communications.

What is the real risk of a poorly executed HTTPS migration?

Let’s be honest: a HTTPS migration without a 301 is one of the most expensive SEO mistakes one can make. You invalidate years of link building work, on-page optimization, domain authority. And the worst part is that it doesn't show immediately. Users access the site normally, the client is satisfied, and three weeks later the disaster appears in the Analytics dashboards.

Another underestimated risk: internal and external links. If your pages continue to point to HTTP in the source code, Google crawls these URLs, encounters your 301s, consuming crawl budget unnecessarily. Update all your internal links to HTTPS immediately after migration. For external backlinks, you can’t do anything directly, but the 301s do the job.

How to correctly configure 301 redirects for a HTTPS migration?

First step: identify all HTTP URLs currently indexed by Google. Export them from Search Console (Performance > Pages) and from your XML sitemap. Create an exact mapping: each HTTP URL must point to its HTTPS equivalent with a 301. No shortcuts to the homepage, no approximate global redirects.

Then implement the redirects at the server level. On Apache, use .htaccess with a RewriteCond rule that checks the protocol and redirects while preserving the full path. On Nginx, use a return 301 directive in the server block. On CDNs like Cloudflare, set up Page Rules in Permanent Redirect 301 mode. Test with curl or a raw header analysis tool to ensure the server returns a 301, not a 302 or 307.

What technical errors must be absolutely avoided?

Classic error: redirecting all HTTP URLs to the HTTPS homepage. Google interprets this as content removal, not migration. You lose link equity on all your internal pages. Each URL must point to its exact HTTPS equivalent.

Another pitfall: forgetting the variations with and without www. If your site is accessible at http://example.com, http://www.example.com, https://example.com, and https://www.example.com, you must canonicalize to A SINGLE version (usually https://www.example.com or https://example.com depending on your choice) and redirect all others with a 301. Otherwise, you dilute your signals across four versions of URLs.

How to verify that your HTTPS migration is successful from an SEO perspective?

Use Google Search Console to monitor indexing. Add the HTTPS version as a new property (if not already done), submit the HTTPS sitemap, and monitor the coverage report. You should see HTTP URLs gradually replaced by their HTTPS version in the index. This process usually takes 2 to 6 weeks depending on site size.

At the same time, check with Screaming Frog or an equivalent crawler that all your HTTP URLs correctly return a 301 to HTTPS. Look for redirect chains (HTTP > HTTP > HTTPS for example), loops, accidental 302s or 307s. Crawl the HTTPS version also to ensure no internal links still point to HTTP.

• Map each HTTP URL to its exact HTTPS equivalent
• Configure 301 redirects at the server level (.htaccess, nginx.conf, CDN)
• Test with curl or a raw HTTP header analyzer, not just in a browser
• Update all internal links to HTTPS in the source code
• Submit the HTTPS sitemap in Google Search Console
• Monitor reindexing for a minimum of 4-6 weeks