Audit your domain's 4-variant HTTPS redirect convergence, full SSL certificate chain (for mobile & AI crawlers), TLS handshake speed, mixed content, and hidden SEO http:// leaks.
Your domain can be accessed four ways: http://, http://www., https://, and https://www.. All three non-canonical versions should 301 redirect in a single hop to your primary https:// URL so link equity is never split.
Desktop browsers silently download missing intermediate SSL certificates, hiding server misconfigurations. Headless crawlers like GPTBot, ClaudeBot, PerplexityBot, and mobile Safari strictly require your server to send the full certificate chain (fullchain.pem).
Even when a page loads with a padlock, leftover http:// URLs inside <link rel="canonical">, JSON-LD Schema, or your robots.txt Sitemap directive send conflicting signals to Googlebot and waste crawl budget on redirect hops.