What Is an SSL Certificate Checker?
An SSL certificate checker connects to a domain's HTTPS endpoint to retrieve certificate details — issuer, validity dates, common name, SANs, and the number of certificates issued via Certificate Transparency logs. HTTPS has been a confirmed Google ranking signal since 2014, and Chrome shows "Not Secure" warnings for HTTP sites.
SSL Expiry: A Silent SEO Killer
An expired SSL certificate causes browsers to display a hard security warning before users can access the site. Organic traffic drops to near zero within days as users bounce and Googlebot encounters errors. Always monitor SSL expiry dates — set calendar reminders 30 days before expiry or use certificate monitoring services.
HTTPS Misconfiguration Issues to Watch For
Having an SSL certificate doesn't automatically mean your site is fully secure. Common misconfigurations include mixed content (HTTP resources on HTTPS pages), HTTP pages that don't redirect to HTTPS, missing HSTS headers, and incorrect certificate chain installation. Each of these can trigger browser warnings or reduce the SEO value of your HTTPS migration.