Verify SSL/TLS certificate details for any domain.
SSL/TLS certificates encrypt the connection between a website and its visitors. When you see the padlock icon in your browser, that's an active certificate protecting data like passwords, credit cards, and personal info in transit.
Certificate expiry is one of the most common causes of unexpected downtime. When a certificate lapses, browsers show full-page warning screens that block all traffic — costing thousands of lost visitors within hours.
This tool reveals the issuing authority, validity period, days remaining, protocol version, and signature algorithm for any domain. Check your certificates regularly to renew before they expire.
Enter the domain above and click Check. You will see the issuer, expiry date, days remaining, TLS protocol version, and whether the certificate chain is trusted.
Browsers show a security warning and block visitors from reaching your site. Check certificates regularly and renew before expiry — often every 90 days with Let's Encrypt.
Yes. No signup required. The check connects directly to the domain's server and returns results in seconds.
This tool opens a live TLS connection to the hostname you enter and reads the certificate the server presents on port 443. You see the subject, Subject Alternative Names (where exposed), issuing Certificate Authority, validity window, days remaining, serial, signature algorithm, and negotiated protocol version. The status badge reflects whether the leaf certificate looks currently usable for browsers and how urgently renewal is needed.
SSL problems are one of the fastest ways to lose trust: visitors see interstitial warnings, APIs reject connections, and payment flows abort. Checking the live edge — not only the file on disk — matters because CDNs, load balancers, and origin servers can each present different certificates.
Valid with comfortable days remaining — healthy; keep automated renewal monitored. Expiring soon (under ~30 days) — treat as urgent; silent renewal failures are common. Invalid, expired, or hostname mismatch — browsers will warn or block; fix before campaigns or launches.
Confirm the name you typed matches what customers use (www vs apex). A certificate for www.example.com alone will fail on bare example.com unless a SAN or separate cert covers it. Issuer should be a publicly trusted CA for public sites — self-signed certs are fine for lab use only.
If the checker disagrees with your browser, you may be hitting a different PoP, an IPv6 vs IPv4 path, or a cached HSTS/pinning state. Compare apex and www separately.
An e-commerce store lost weekend sales when Let’s Encrypt expired Saturday night. On Friday the SSL checker already showed single-digit days remaining. Staging a renewal alert at 14 days — and verifying both www and apex — prevents that class of outage. Pair this tool with Security Headers so HSTS is not enabled until HTTPS is solid on every hostname you serve.
We inspect the certificate presented on port 443 for the hostname you enter from our network vantage point. We do not replace a full PKI audit, client-certificate testing, or continuous multi-region monitoring. Chain trust, OCSP stapling quirks, and every subdomain are out of scope here — use the Health Check for a broader snapshot and your CA/CDN dashboards for automation.
What Is SSL? · DNS, Email & SSL Checklist · How We Grade Website Health · Header Inspector · Security Headers Analyzer