Website Migration from HTTP to HTTPS

HTTP to HTTPS Migration

Switching to HTTPS is a technically straightforward task, but it is often done carelessly. Result: mixed content, loss of traffic due to redirect chains, duplication in search engines.

SSL Certificate

Let's Encrypt — free, automatically updated, sufficient for most sites:

# Certbot on Ubuntu
sudo apt install certbot python3-certbot-nginx
sudo certbot --nginx -d mysite.com -d www.mysite.com

# Auto-renewal (already configured by Certbot)
sudo systemctl enable certbot.timer

Paid certificates (Sectigo, DigiCert) — needed for: EV certificates, wildcard on multiple levels, organization validation (OV).

Nginx: HTTPS + HTTP→HTTPS Redirect

# HTTP → HTTPS redirect
server {
    listen 80;
    server_name mysite.com www.mysite.com;
    return 301 https://mysite.com$request_uri;  # without www
}

# HTTPS
server {
    listen 443 ssl http2;
    server_name mysite.com;

    ssl_certificate     /etc/letsencrypt/live/mysite.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/mysite.com/privkey.pem;

    # Modern TLS configuration (Mozilla SSL Config Generator)
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;

    # HSTS (add only after verifying HTTPS works!)
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

    # ...rest of configuration...
}

Fixing Mixed Content

After switching, the browser blocks HTTP resources on HTTPS pages. Find them:

# Scan for mixed content
npx mixed-content-scanner https://mysite.com

# Or in Chrome DevTools: Console → filter "Mixed Content"

In WordPress — use Better Search Replace plugin to replace http:// → https:// in database.

For other CMS:

-- PostgreSQL
UPDATE posts SET content = replace(content, 'http://mysite.com', 'https://mysite.com');
UPDATE posts SET content = replace(content, 'http://old-cdn.com', 'https://new-cdn.com');

Updating GSC and Yandex Webmaster

• Add HTTPS version as a separate resource
• Set as primary version
• Update sitemap URL (https://)
• Configure preferred domain = https://mysite.com (without www)

Post-Migration Checklist

• All pages open via HTTPS
• HTTP redirects to HTTPS (301)
• www redirects to non-www (or vice versa)
• Canonical tags point to HTTPS
• Sitemap contains HTTPS URLs
• No mixed content warnings
• HSTS header present
• SSL Labs rating A or A+

Switching standard site to HTTPS — 4–8 hours.