SSL Checker
Inspect SSL certificates, chain validation, expiry and protocol configuration for any HTTPS host.
Frequently Asked Questions
What does an SSL certificate do?
An SSL/TLS certificate establishes an encrypted connection between a browser and web server, ensuring data in transit cannot be intercepted or modified. It also authenticates the server's identity so visitors know they are communicating with the legitimate site. Modern browsers show a padlock icon for sites with valid certificates and warn users about sites without them.
What is SSL chain validation?
SSL certificates are signed by intermediate Certificate Authorities (CAs), which are in turn signed by root CAs trusted by browsers and operating systems. Chain validation verifies that every certificate in the chain is valid, unexpired, and correctly signed. A broken chain (e.g., missing intermediate certificate) causes browser warnings even if the end-entity certificate itself is valid.
How far in advance should I renew my SSL certificate?
Renew at least 30 days before expiry to allow time for validation, issuance, and deployment without service disruption. With Let's Encrypt and automated ACME clients (Certbot, acme.sh), certificates renew automatically when 30 days or fewer remain. For organisation-validated (OV) or extended-validation (EV) certificates, which require manual vetting, allow 2–4 weeks for the CA to complete verification.
What is the difference between DV, OV and EV certificates?
DV (Domain Validated) only proves you control the domain — issued in minutes, used by most websites. OV (Organisation Validated) also verifies your organisation's legal existence — takes 1–3 days, shows the org name in certificate details. EV (Extended Validation) requires the most rigorous vetting — historically showed a green bar, but modern browsers no longer display it prominently. DV is sufficient for most sites; OV/EV add credibility for financial and e-commerce sites.