SSL Checker
Articles, guides, and in-depth tips for the SSL Checker — everything you need to get the most out of it.
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Your SSL Certificate Was Valid Yesterday — Here's How It Can Fail Today Without You Changing Anything
SSL Certificate Expiry Fails Silently — Here's Every Way Automated Renewal Can Break Without Warning
SSL certificate expiry gives no visible warning until the moment it fails — and then every visitor simultaneously sees a hard browser error. Here's why automated renewal (Let's Encrypt + Certbot) fails silently in specific patterns (the cron job stops, the web server never reloads, domain validation breaks), why external expiry monitoring is essential even with automation, and the certificate-pinning complication for mobile apps.
Certificate Transparency: How Public Logs Reveal Every SSL Certificate Ever Issued for Your Domain
Every publicly-trusted SSL certificate issued since 2018 is recorded in public, cryptographically verifiable logs — and browsers won't trust a certificate without proof of logging. Here's why Certificate Transparency exists, how CT logs let you discover every certificate ever issued for your domain (including ones you didn't request), and how CAA records complement CT for security monitoring.
TLS Configuration Beyond Certificates: Versions, Cipher Suites, HSTS, and OCSP Stapling
TLS 1.0 and 1.1 are still enabled on more servers than they should be. Here's TLS version history and current status, what cipher suites determine (including forward secrecy), HSTS preloading requirements, OCSP stapling, and how to use SSL Labs to grade your TLS configuration.
SSL Certificate Types: DV vs OV vs EV, Certificate Chains, and Preventing Expiry Outages
DV, OV, and EV certificates verify different things. Let's Encrypt is as secure as paid certs for encryption. The chain matters as much as the certificate itself. Here's what SSL certificates actually prove and how to prevent expiry outages.
SSL Checker — Verify Certificate Validity, Expiry & Chain Instantly
Learn how SSL certificates work, what DV/OV/EV and wildcard certificates mean, how to read SSL checker results, and how to catch certificate expiry before users see browser security warnings.
