HTTPS is the baseline expectation for any website today. Chrome labels HTTP sites “Not Secure.” Users hesitate to enter information. Google confirmed HTTPS as a ranking signal in 2014 and has steadily increased its weight since. Running HTTP creates friction with users, browsers, and search engines simultaneously.
The migration itself carries risk. URL changes, redirect implementations, and certificate configurations can each cause problems. Sites have lost significant traffic from botched HTTPS migrations. But the risks are manageable with proper planning, and the cost of staying on HTTP grows each month.
This guide covers the migration process from planning through verification, with emphasis on the SEO-specific concerns that determine whether migration helps or hurts rankings.
Why HTTPS Matters for SEO
Google confirmed HTTPS as a lightweight ranking signal. Lightweight means it will not transform rankings alone, but among otherwise equal pages, HTTPS has an advantage. Over time, Google has indicated this signal has strengthened.
Indirect ranking factors also matter. User trust metrics likely influence rankings indirectly. If users see “Not Secure” and bounce, that behavior pattern signals quality problems. Conversion rates on HTTP sites consistently trail HTTPS equivalents.
Chrome displays “Not Secure” prominently for HTTP sites, especially on pages with forms. Other browsers have similar warnings. These warnings affect user behavior regardless of SEO.
HTTPS to HTTP referral data is stripped for privacy. If your site runs HTTP and receives traffic from HTTPS sites, which now includes most major sites, you lose referrer information in analytics. HTTPS preserves this data.
Certificate Types and Selection
SSL and TLS certificates come in three validation levels. For SEO purposes, they are functionally identical. Google does not differentiate ranking treatment by certificate type.
Domain Validated certificates validate only that you control the domain. They are issued within minutes, least expensive, and often free via Let’s Encrypt or Cloudflare.
Organization Validated certificates validate domain control plus organizational identity. They take days to issue and have moderate cost.
Extended Validation certificates require rigorous organizational verification. They historically showed company name in the browser bar, though most browsers have removed this distinction. They have higher cost and longer issuance time.
Recommendation: DV certificates work for most sites. Let’s Encrypt provides free DV certificates with automated renewal. Choose OV or EV only if your organization requires it for compliance or brand trust reasons, not for SEO.
Certificate considerations include ensuring the certificate covers all subdomains with a wildcard or obtaining separate certificates, setting up automated renewal since Let’s Encrypt certificates expire every 90 days, and verifying the certificate chain is complete with intermediate certificates included.
Pre-Migration Preparation
Preparation prevents the problems that cause traffic loss.
Crawl your HTTP site completely. Document every URL with traffic or rankings. This becomes your redirect mapping baseline. Export rankings data for comparison post-migration. For local businesses, pay special attention to location-specific pages. A Nashville, TN contractor should ensure all neighborhood and service area pages are mapped correctly before migration begins.
Audit existing redirects. Document all current redirect rules. These must be updated for HTTPS. Existing chains will become longer if not handled properly.
Check for hardcoded HTTP URLs. Internal links, image sources, script references, and CSS URLs hardcoded as http:// will cause mixed content issues. Identify these for updating.
Update third-party integrations. Services embedded on your site including analytics, ads, and widgets should use HTTPS. Verify all third-party scripts support HTTPS.
Configure staging environment. Test the entire migration in staging first. Identify issues before they affect production.
Set expectations. Inform stakeholders that traffic fluctuation during migration is normal. Recovery typically takes 4 to 8 weeks for large sites.
Implementation Steps
Step 1: Install SSL certificate. Install the certificate on your server. Verify it is working by accessing https://yourdomain.com directly. Check for certificate errors.
Step 2: Update internal references. Change all internal links, canonical tags, hreflang annotations, and sitemap URLs to HTTPS. This can be done via database search-and-replace for CMS sites, code changes for custom implementations, or using protocol-relative URLs or relative URLs where possible.
Step 3: Implement redirects. 301 redirect all HTTP URLs to HTTPS equivalents at the server level.
Step 4: Fix mixed content. Mixed content occurs when HTTPS pages load HTTP resources. Browsers block some mixed content and warn about the rest. Common mixed content sources include images with hardcoded HTTP src, scripts loaded via HTTP, CSS files via HTTP, fonts via HTTP, and iframes with HTTP sources. Use browser developer tools to identify mixed content. Console shows warnings and Security panel shows details.
Step 5: Update canonical tags. All canonical tags should reference HTTPS URLs. Canonical pointing to HTTP while page is HTTPS creates conflicting signals.
Step 6: Update XML sitemap. Generate new sitemap with HTTPS URLs. Submit to Search Console.
Step 7: Update robots.txt. If robots.txt references your sitemap or specific URLs, update to HTTPS.
Search Console Configuration
Add HTTPS property in Google Search Console. Add your HTTPS site as a new property. You need both HTTP and HTTPS properties during transition to monitor both.
Domain property option covers both protocols automatically if using domain-level verification.
Submit HTTPS sitemap to the HTTPS property.
Monitor both properties. Watch HTTP property for crawl errors indicating redirect issues. Watch HTTPS property for indexing progress.
Change of Address tool is not required for HTTP to HTTPS migration on the same domain. Google handles this automatically through redirects.
Post-Migration Verification
Check redirect functionality by testing multiple URL patterns: homepage, category pages, product and article pages, URLs with parameters, URLs with trailing slashes, and old redirect destinations to verify chains are not forming.
Monitor Search Console coverage report for indexing status. Watch for HTTP URLs decreasing as indexed, HTTPS URLs increasing as indexed, redirect errors, and crawl anomalies.
Check mixed content using online tools like WhyNoPadlock or JitBit SSL Checker to scan for mixed content across the site.
Verify external tools by updating URLs in Google Analytics default URL setting, Google Business Profile, social media profiles, email signatures and templates, and third-party platform integrations.
Monitor rankings. Some fluctuation is normal. Track key rankings daily during the first two weeks, then weekly for two months. Significant sustained drops indicate problems to investigate.
Expected timeline: Days 1 through 3 see redirects working and initial HTTPS crawling. Weeks 1 through 2 show mixed indexing and fluctuating rankings. Weeks 3 through 4 show majority HTTPS indexed. Weeks 5 through 8 bring stabilization with HTTP mostly deindexed. Month 3 and beyond shows full HTTPS indexing and stable rankings.
Common Migration Mistakes
Redirect loops occur when HTTPS rules conflict with www and non-www rules. Test all combinations: http://example.com, http://www.example.com, https://example.com, and https://www.example.com. All should reach one final destination with a single redirect.
Redirect chains form when existing redirects add another hop from HTTPS migration. Flatten chains by updating all redirects to point directly to the final HTTPS URL.
Mixed content is often overlooked in unexpected places: user-generated content, old blog posts with embedded images, and third-party widgets. Comprehensive auditing prevents issues.
Forgetting subdomains causes problems because each subdomain needs its own HTTPS configuration. m.example.com, blog.example.com, and shop.example.com each require certificates and redirects.
Internal links not updated means relying solely on redirects for internal navigation, which works but wastes redirect hops. Update internal links to HTTPS directly.
Certificate expiration catches sites off guard. Let’s Encrypt certificates expire every 90 days. Automated renewal prevents embarrassing security warnings.
HSTS Implementation
HTTP Strict Transport Security tells browsers to only connect via HTTPS, even if users type HTTP.
Benefits include preventing protocol downgrade attacks, eliminating HTTP-to-HTTPS redirect for returning visitors, and signaling strong HTTPS commitment.
Implementation caution: only implement HSTS after confirming HTTPS works completely. HSTS errors are difficult to reverse because browsers cache the directive.
Recommended rollout: start with short max-age of 300 seconds to test, increase gradually to 86400 then 604800 then 31536000, add includeSubDomains only after all subdomains have HTTPS, and consider HSTS preloading for maximum security.
Troubleshooting Common Issues
Rankings dropped significantly: verify redirects return 301 not 302, check for redirect chains or loops, confirm canonical tags point to HTTPS, look for crawl errors in Search Console, and verify no noindex tags were accidentally added.
Mixed content warnings persist: use browser developer tools to identify specific resources, check user-generated content areas, audit third-party scripts, and look for CSS files loading HTTP resources like background images and fonts.
Some pages not redirecting: check for conflicting redirect rules, verify rules apply to all URL patterns, test with query strings and edge cases, and review CDN or caching layer configurations.
Certificate errors: verify intermediate certificates are installed, check certificate matches domain including www and non-www, confirm certificate is not expired, and test across different browsers.
HTTPS migration is a one-time infrastructure change with permanent benefits. The technical work is finite and manageable. The SEO benefits, while individually small, compound with user trust improvements and browser compatibility. There is no strategic reason to delay migration, only execution risk that proper preparation mitigates.
Sources
- Google Search Central: Secure Your Site with HTTPS – https://developers.google.com/search/docs/crawling-indexing/https
- Google Security Blog: HTTPS as a Ranking Signal – https://security.googleblog.com/2014/08/https-as-ranking-signal_6.html
- Google Search Central: Site Move with URL Changes – https://developers.google.com/search/docs/crawling-indexing/site-move-with-url-changes
- Let’s Encrypt Documentation – https://letsencrypt.org/docs/
- Mozilla: HTTP Strict Transport Security – https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security