Real-Time TLS / SSL Diagnostic Tool

Free SSL Certificate & Expiry Checker

Inspect your website's SSL/TLS certificate health, days until expiry, Certificate Authority (CA) issuer, Subject Alternative Names (SANs), and cryptographic cipher security.

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Why Regular SSL & TLS Audits Matter

An expired or misconfigured SSL certificate triggers harsh full-page browser security warnings ("Your connection is not private"), devastating user trust, conversion rates, and SEO search rankings.

Prevent Costly Outages

Automate certificate renewal reminders and verify automated ACME/Let's Encrypt cron renewals before your website goes dark.

Protect Google SEO Rank

HTTPS encryption is a verified Google search ranking factor. Unbroken SSL trust ensures continuous indexability.

Customer Data Privacy

Modern TLS 1.3 encryption with 256-bit AES/ChaCha20 ciphers protects credit card payments, passwords, and form submissions from eavesdropping.

Frequently Asked Questions

What causes the "NET::ERR_CERT_COMMON_NAME_INVALID" error?

This error occurs when the domain name in the browser address bar does not match any of the Common Names (CN) or Subject Alternative Names (SANs) listed inside the server's SSL certificate.

What is the difference between TLS 1.2 and TLS 1.3?

TLS 1.3 simplifies the cryptographic handshake from 2 round-trips to 1 round-trip (0-RTT resumption), reducing latency by up to 30% while eliminating vulnerable legacy cipher suites.

How often should SSL certificates be renewed?

Commercial certificates are valid for a maximum of 398 days (approx 13 months), while Let's Encrypt certificates are valid for 90 days with recommended auto-renewal every 60 days.

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