Inspect any domain’s SSL certificate in one click. Get the issuer, expiry date, days remaining, key size, signature algorithm, version, serial number, and every Subject Alternative Name, fetched live by connecting to port 443 and parsing the X.509 certificate.
Type any domain like example.com or paste a full URL.
See an instant status banner: valid, expiring soon, or invalid.
Read the issuer, expiry date, key size, and full SAN list.
An expired SSL cert breaks every page on a site, blocks payments, and wrecks search rankings. The checker shows expiry date, issuer, key size, and full SAN list in one scan, so renewal never sneaks up on you.
Run it monthly on every domain you operate, and add 30-day-before-expiry alerts for the ones you cannot afford to drop.
The tool opens a real TLS connection to your domain on port 443, captures the peer certificate during the handshake, and parses it via OpenSSL. So you see the actual certificate the server presents, not a cached database lookup that may be days out of date.
A colored status banner instantly classifies the certificate: green if valid with 30+ days left, amber if it expires in 8-30 days, red if it expires in 7 days or less, and red-fail if it is already expired. Use this in monitoring runbooks to catch renewals before they go down.
Get every detail in one report: validity window, issuer CN + organization, subject CN + organization, signature algorithm (e.g. SHA256-RSA), public key size in bits, serial number, certificate version (X.509 v3), and the complete list of Subject Alternative Names, rendered as monospace pills.
No account, no API key, no rate limit nags. Submit any public domain, get a complete certificate audit. Works for your own sites, your competitors, your customers, or any domain you need to verify before a launch.
More SEO tools you might find useful.
Common questions about SSL certificates and this checker.
