SSL Certificate Checker

What Are SSL/TLS Certificates?

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that establish an encrypted connection between a web server and a browser. An SSL/TLS certificate is a digital document that authenticates a website's identity and enables encrypted communication. When a browser connects to a website over HTTPS, the server presents its SSL certificate, which the browser validates against a list of trusted Certificate Authorities (CAs). If the certificate is valid and trusted, a secure encrypted session is established using a process called the TLS handshake. This encryption protects sensitive data -- such as login credentials, payment information, and personal details -- from being intercepted by attackers during transit.

Types of SSL Certificates: DV, OV, and EV

SSL certificates come in three validation levels, each offering a different degree of identity verification:

• Domain Validated (DV) -- The most basic type of SSL certificate. The CA only verifies that the applicant controls the domain. DV certificates are issued quickly (often within minutes) and are commonly used by blogs, personal websites, and small projects. Let's Encrypt provides free DV certificates.
• Organization Validated (OV) -- The CA verifies both domain ownership and the identity of the organization requesting the certificate. OV certificates display the organization name in the certificate details and provide a higher level of trust for business websites.
• Extended Validation (EV) -- The highest level of SSL validation. The CA conducts a thorough vetting process, including verifying the legal, physical, and operational existence of the organization. EV certificates are typically used by banks, financial institutions, and large e-commerce platforms.

Why HTTPS Matters and Monitoring Certificate Expiration

HTTPS is no longer optional for modern websites. Search engines like Google use HTTPS as a ranking signal, meaning sites with valid SSL certificates may receive a boost in search results. Browsers now display prominent warnings when users visit sites without HTTPS, which can significantly reduce visitor trust and engagement. Beyond SEO and user experience, HTTPS is required for modern web features such as HTTP/2, service workers, and the Geolocation API.

SSL certificates have a defined validity period, typically ranging from 90 days (Let's Encrypt) to one year. An expired SSL certificate causes browsers to display security warnings that block most visitors from accessing your site. Regular monitoring of certificate expiration dates is essential to avoid unexpected downtime. Our free SSL certificate checker tool lets you instantly verify the certificate status, issuer, expiration date, protocol version, and Subject Alternative Names (SANs) for any website, helping you ensure that your SSL configuration is correct and your certificates remain valid.