🔐 SSL Certificate Checker

Check SSL certificate details for any domain, including expiration dates, issuer information, validity period, and certificate chain details. Quickly verify if a website's SSL certificate is valid and properly configured.

Enter Domain Name:

💡 Tip: Enter just the domain name (without http:// or https://). The checker will automatically verify the SSL certificate for that domain.

Enter a domain and click "Check SSL Certificate" to view certificate details.

Want to be told before it expires?
A certificate check is only true for the moment you ran it. Set up a free daily watch and we will email you before this certificate lapses - and if its DNS records change.

What the check does, and what it leaves out

The domain you type is sent to the SimpleMoney API, which opens a TLS connection to it on port 443 and reads the certificate the server presents. Back come the notBefore and notAfter dates, the days remaining, and the subject and issuer distinguished names field by field. The badge is a simple threshold: green above 30 days, amber below, red once notAfter has passed.

That is a certificate readout, not an audit. Nothing here validates the chain up to a trusted root, checks that the hostname appears in the SAN list, asks an OCSP responder whether the certificate was revoked, or looks at which TLS versions and cipher suites the server will negotiate. For those, connect yourself:

openssl s_client -connect example.com:443 -servername example.com </dev/null \
  | openssl x509 -noout -dates -subject -issuer -ext subjectAltName

The connection is made from AWS, not from your desk. If a corporate proxy re-signs traffic on your network, your browser sees the proxy's certificate and this page sees the real one - which is exactly how you tell the two situations apart.

Using the result

Only public hosts on 443 can be checked. There is no port field, and a name that resolves only inside your network will fail.
A CDN may answer differently. Geo-routed sites can serve one certificate to us-east-1 and another to you.
The alert box under a result will email you before that certificate expires, which is the part worth setting up once rather than remembering to come back.

Frequently asked questions

How many days before expiry should I renew a certificate?

Renew at a third of the lifetime remaining, and automate it. ACME clients renew a 90-day certificate at 30 days left; as issuance limits fall towards 47 days, manual renewal stops being viable at all.

Why does this show a different certificate from my browser?

Something between you and the site is terminating TLS - usually a company inspection proxy or antivirus, occasionally a captive portal. It can also be a CDN answering the two locations from different edges.

Can I check a certificate on port 8443 or an internal server?

Not from here. Use openssl s_client -connect host.internal:8443 on a machine that can reach it; the same flags work for any port.