SSL Health & Security Check
Scan your website's SSL/TLS configuration, verify certificate chain validity, and detect deprecated protocols in seconds.
Understanding SSL/TLS Handshakes and Chain Validation
An SSL/TLS certificate encrypts communication between users and your web servers, establishing identity and data privacy. Modern web security mandates robust TLS 1.3 encryption, trusted Certificate Authority (CA) intermediate bundling, and strict expiration monitoring to prevent silent downtime.
1. TLS Handshake Negotiation
Our edge probe initiates a secure TLS handshake against your hostname, testing cipher suite negotiation and protocol support (TLS 1.2 and TLS 1.3).
ClientHello -> ServerHello (TLS_AES_256_GCM_SHA384)2. Certificate Chain Verification
We inspect the leaf certificate, intermediate CA certificates, and root trust store anchors to ensure mobile and browser clients do not encounter untrusted authority warnings.
Leaf -> Intermediate CA -> Root CA3. Expiry & Security Flags
We calculate exact days until expiration, SAN (Subject Alternative Names) matching, OCSP stapling status, and HSTS response headers.
Strict-Transport-Security: max-age=31536000Common SSL/TLS Vulnerabilities & How to Fix Them
Expired Certificates (NET::ERR_CERT_DATE_INVALID)
Critical OutageAutomated ACME/Let's Encrypt renewal scripts can fail silently due to rate limits or DNS authorization errors. SteadyStack alerts you 30, 14, and 7 days prior to expiry.
Broken Intermediate Trust Chains
Chain GapIf your web server (Nginx/Caddy/Apache) only serves the leaf certificate without fullchain.pem, desktop browsers with cached CAs may work while mobile apps crash.
Deprecated TLS 1.0 & TLS 1.1 Support
ComplianceLegacy protocols contain known cryptographic flaws (POODLE, BEAST). Modern compliance frameworks (PCI-DSS, SOC 2, HIPAA) require disabling TLS versions below 1.2.
Missing HSTS Preloading
Security HeaderWithout HTTP Strict Transport Security, users visiting http:// can be intercepted via SSL stripping attacks before being redirected to https://.
Frequently Asked Questions
Everything you need to know about SSL Certificate Checker and network reliability best practices.
How far in advance should I renew my SSL certificate?
Best practices recommend renewing SSL/TLS certificates at least 30 days before expiration. Most automated ACME clients (like Certbot) automatically renew at 30 days remaining.
What is the difference between TLS 1.2 and TLS 1.3?
TLS 1.3 reduces the handshake round-trips from 2-RTT to 1-RTT (or 0-RTT with session resumption), significantly improving latency while removing vulnerable legacy cipher suites.
Why does my SSL work on desktop Chrome but fail on mobile?
Desktop browsers frequently cache intermediate certificates, masking incomplete server certificate bundles. If the server does not send the full chain, mobile devices with strict trust stores will reject the connection.
Can SteadyStack automatically monitor my SSL certificate expiry?
Yes. SteadyStack monitors SSL certificate validity, expiration dates, and revocation statuses across global edge nodes, delivering instant alerts via Slack, Discord, Email, and PagerDuty.
Automate Your Monitoring 24/7 with SteadyStack
Don't wait for manual tests. SteadyStack pings your endpoints from global edge locations every 60 seconds with quorum consensus to eliminate false alarms.