Free SSL Checker & Expiration Auditor
Verify SSL/TLS certificate validity, expiration date, SANs, cipher suites, and chain security instantly.
Connecting and inspecting SSL handshake...
Checking certificates, expiration timestamps, TLS cipher suite, and certificate chains.
example.com
Issued by Let's Encrypt Authority
Certificate Specifications
| Common Name (CN) | |
|---|---|
| Certificate Issuer | |
| Validity Period |
Valid From:
Valid Until:
|
| Signature Algorithm | |
| Serial Number | |
| Self-Signed Status | |
| SAN Domains |
Understanding SSL/TLS Certificates and Website Security
An SSL (Secure Sockets Layer) and its modern successor TLS (Transport Layer Security) certificate is the bedrock of internet trust and cybersecurity. It establishes an encrypted cryptographic tunnel between a client browser and your web server, protecting sensitive data—such as credit card numbers, passwords, session tokens, and personal details—from eavesdropping, man-in-the-middle (MITM) attacks, and packet sniffing.
Why Regular SSL Audits Are Essential for Every Webmaster
Prevent Costly Downtime
Expired certificates trigger alarming browser warnings ("Your connection is not private") that immediately drive away over 90% of prospective visitors, damaging revenue and brand credibility.
Preserve Google SEO Rankings
HTTPS is a confirmed Google core ranking signal. A misconfigured or expired certificate drops search ranking positions and flags your site in Google Search Console.
Verify Intermediate Certificate Chains
Missing intermediate CA certificates often load fine on desktop Chrome due to local OS caching, but fail completely on mobile Safari and Android devices.
Detect Insecure Ciphers & TLS 1.0/1.1
Modern cybersecurity standards (PCI-DSS, HIPAA) mandate TLS 1.2 or TLS 1.3 with strong forward-secrecy cipher suites like ECDHE-RSA-AES256-GCM.
How to Use This Online SSL Checker
- Enter your domain name (e.g.
vibetool.orgorexample.com). - Optionally specify the secure port (default is
443for HTTPS). - Click Check SSL to initiate an active TLS handshake audit.
- Review your certificate validity dates, remaining days until expiration, issuer authority, SAN domain list, and encryption cipher.
Frequently Asked Questions (FAQ)
domain.com, www.domain.com, mail.domain.com) to be secured under a single SSL certificate without purchasing separate certificates for each subdomain.