What is the difference between SSL and TLS?

SSL (Secure Sockets Layer) is the older protocol; TLS (Transport Layer Security) is its modern, more secure successor. While most certificates today use TLS 1.2 or TLS 1.3, they are still commonly referred to as SSL certificates. The terms are often used interchangeably.

Does having an SSL certificate affect SEO?

Yes. Google confirmed HTTPS as a ranking signal in 2014. Websites with valid SSL certificates rank higher than equivalent HTTP sites. Additionally, Chrome and other browsers mark HTTP sites as 'Not Secure', which increases bounce rates and harms rankings indirectly.

What is a Certificate Authority (CA)?

A Certificate Authority (CA) is a trusted organisation that issues SSL/TLS certificates. Well-known CAs include Let's Encrypt, DigiCert, Comodo, GlobalSign, and Sectigo. Browsers trust certificates from recognised CAs, which is what makes HTTPS connections secure.

SSL Checker Tool

Instantly verify any website's SSL certificate — check validity, expiry date, issuer, and full HTTPS security details. Free, no login required.

What Is an SSL Certificate?

An SSL certificate (Secure Sockets Layer) is a digital certificate that authenticates a website's identity and enables encrypted communication between the web server and a visitor's browser. It is what makes a site's address begin with HTTPS instead of HTTP, and what displays the padlock icon in your browser's address bar.

Without a valid SSL certificate, browsers like Chrome, Firefox, and Safari display a "Not Secure" warning to visitors — damaging trust, increasing bounce rates, and hurting your search rankings. Google has used HTTPS as a ranking signal since 2014.

How Does This SSL Checker Work?

Enter any domain name (e.g. example.com) and click Check SSL. The tool connects to the domain over port 443 (the standard HTTPS port), retrieves its SSL/TLS certificate, and parses all key fields into a readable table.

This is useful for:

Checking how many days remain before your SSL certificate expires
Verifying which Certificate Authority (CA) issued your certificate
Confirming that the correct domain is covered by the certificate
Diagnosing HTTPS warnings and browser security errors
Auditing third-party or client websites for security compliance

SSL Certificate Fields Explained

Field	Description
Domain	The domain name the SSL check was performed on.
Common Name (CN)	The domain name (or wildcard, e.g. `*.example.com`) the certificate was issued for. Must match the domain being visited.
Issuer	The Certificate Authority (CA) that issued and vouches for the certificate (e.g. Let's Encrypt, DigiCert, Comodo).
Valid From	The date the certificate became active. Connections before this date are not trusted.
Valid To	The certificate expiry date. After this date the certificate is invalid and browsers will show a security warning.
Serial Number	A unique identifier assigned by the CA to this specific certificate. Used for tracking and revocation.
Signature Algorithm	The cryptographic algorithm used to sign the certificate (e.g. `sha256WithRSAEncryption`). Determines the strength of the certificate's security.

SSL vs TLS — What Is the Difference?

SSL (Secure Sockets Layer) is the original encryption protocol developed in the 1990s. TLS (Transport Layer Security) is its modern, more secure replacement. Despite most connections today using TLS 1.2 or TLS 1.3, the industry still refers to certificates as "SSL certificates" — the terms are largely interchangeable in everyday use.

TLS 1.3 — The latest and most secure version. Faster handshakes and stronger encryption. Recommended for all modern servers.
TLS 1.2 — Still widely supported and considered secure when configured correctly.
TLS 1.0 / 1.1 — Deprecated and considered insecure. Browsers no longer support these versions.
SSL 2.0 / 3.0 — Completely obsolete and highly vulnerable. Should never be used.

Frequently Asked Questions

What happens when an SSL certificate expires?

Once expired, browsers display a "Your connection is not private" warning to all visitors. This causes most users to leave immediately, severely damaging traffic and trust. Renew your certificate before the expiry date shown in your SSL results above.

Does SSL affect my Google rankings?

Yes. Google confirmed HTTPS as a ranking signal in 2014. Sites without a valid SSL certificate are at a disadvantage in search rankings compared to HTTPS equivalents. Chrome also labels HTTP pages as "Not Secure", which increases bounce rates and indirectly hurts SEO.

What is a wildcard SSL certificate?

A wildcard certificate (shown as *.example.com in the Common Name field) covers a domain and all its subdomains with a single certificate. For example, it would secure shop.example.com, blog.example.com, and mail.example.com simultaneously.

How do I get a free SSL certificate?

Let's Encrypt is a free, automated Certificate Authority trusted by all major browsers. Most web hosting providers (cPanel, Cloudflare, etc.) offer one-click Let's Encrypt installation. Free certificates are renewed every 90 days, often automatically.

Is this SSL Checker tool free?

Yes, completely free. Simply enter any domain name and instantly retrieve its full SSL certificate details. No account or sign-up is required.