How do I check if a website has a valid SSL certificate?

Simply enter the domain name in our SSL checker and click 'Check SSL'. The tool will instantly analyze the certificate validity, show the issuer, expiration date, and provide a security grade from A+ to F. A valid certificate will show as 'Secure' with a green indicator.

What is the difference between SSL and TLS?

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols for secure communication. TLS is the successor to SSL and is more secure. Modern websites use TLS 1.2 or TLS 1.3, while SSL 3.0 and older versions are deprecated due to security vulnerabilities.

What does HSTS mean and why is it important?

HSTS (HTTP Strict Transport Security) is a security header that tells browsers to only connect via HTTPS. It prevents downgrade attacks and cookie hijacking. Our tool checks if HSTS is enabled, its max-age value, whether it includes subdomains, and if the site is in the preload list.

How can I check when my SSL certificate expires?

Our SSL checker shows the exact expiration date, the number of days remaining, and a visual indicator of certificate health. We recommend renewing certificates at least 30 days before expiry to avoid service interruptions.

What is a certificate chain and why does it matter?

A certificate chain (or trust chain) links your SSL certificate to a trusted root certificate authority (CA) through intermediate certificates. A complete chain is essential for browsers to trust your certificate. Our tool validates the entire chain.

What is a good SSL grade?

An A+ grade indicates excellent SSL/TLS configuration with all security best practices implemented. Grade A is very good, B is acceptable, C needs improvement, D has significant issues, and F indicates critical security problems or an invalid certificate.

Which TLS versions should my server support?

Modern servers should support TLS 1.3 (best) and TLS 1.2 (good). TLS 1.0 and 1.1 are deprecated and should be disabled. SSL 3.0 has critical vulnerabilities (POODLE) and must never be enabled. Our tool checks all protocol versions.

Is this SSL checker free?

Yes, our SSL checker is completely free with no registration required. Get instant results for any domain with detailed security analysis. We don't store your queries or show ads.

ssl-checker

SSL Certificate Checker - Free TLS Security Test

Analyze SSL/TLS certificates instantly. Check certificate validity, expiry dates, protocol support (TLS 1.3/1.2), HSTS configuration, certificate chains, and get a comprehensive security grade. Free, fast, and private.

SSL Certificate Checker

Enter any domain to analyze SSL/TLS security: certificate validity, protocols, security headers, and vulnerabilities.

What You Get

Certificate Details

Subject & Issuer information
Validity period & expiry countdown
Key type and size (RSA/ECDSA)
Subject Alternative Names (SAN)
Signature algorithm

Protocol Support

TLS 1.3 / 1.2 / 1.1 / 1.0 detection
SSL 3.0 vulnerability check
Protocol recommendations
Cipher suite analysis
Forward secrecy support

Security Analysis

HSTS configuration check
Preload list eligibility
Certificate chain validation
DNSSEC status
Overall security grade (A+ to F)

How to Use This Tool

Enter Domain

Type any domain name (e.g., google.com) - no https:// needed

Check SSL

Click Check SSL to analyze the certificate and security configuration

Review Results

Explore tabs for detailed certificate, security, and protocol information

Why SSL/TLS Matters

SSL/TLS certificates encrypt data between your users' browsers and your server, protecting sensitive information like passwords, credit cards, and personal data from interception by attackers.

Search engines like Google prioritize HTTPS websites in search rankings, making valid SSL certificates essential for both security and SEO.

Modern browsers display warnings for sites without valid SSL certificates, which can significantly impact user trust, bounce rates, and conversion rates.

Regular SSL monitoring helps prevent certificate expiration, which can cause service outages and security warnings for your visitors.

Frequently Asked Questions

An SSL certificate checker is a tool that analyzes a website's SSL/TLS certificate and security configuration. It verifies if the certificate is valid, checks the expiry date, validates the certificate chain, tests protocol support (TLS 1.2, 1.3), and evaluates security headers like HSTS.

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