SSL Tools

SSL Certificate Checker

Instantly check a domain's SSL certificate status, expiry date, issuer, and full certificate details.

Enter any domain below to instantly check its SSL certificate - validity, expiry date, issuer, certificate authority, TLS version, and more.

More SSL Tools

View all 3

TLS Version Checker SSL Expiry Checker

JustChecker monitors your SSL certificates automatically and alerts you before they expire - never lose customer trust to a browser warning again.

What Is the SSL Certificate Checker?

It connects to a domain over HTTPS, reads the certificate the server actually presents, and shows whether it is valid, who issued it, which domains it covers and when it expires. It checks the live server, so it shows exactly what visitors' browsers receive right now.

When to Use It

After installing or renewing a certificate, to confirm the new one is being served.
When visitors report a "Not secure" or certificate warning.
Before a launch or migration, to make sure www and non-www versions are covered.

How to Use It

Enter a domain such as example.com (no need for https://).
Click Check SSL.
Review the status, issuer, validity dates and covered names.

Understanding the Result

A valid certificate must be within its validity dates, cover the domain you entered (directly or via a wildcard) and be issued by a trusted certificate authority. The days-remaining figure tells you how soon renewal is due - most free certificates last 90 days and should renew automatically about 30 days before expiry.

Limitations

The check uses the standard HTTPS port 443. It shows the certificate for the exact hostname entered, so check subdomains separately. To track only the expiry date use the SSL Expiry Checker, and for protocol details use the TLS Version Checker.

Frequently Asked Questions

It connects to your domain on port 443, retrieves the live certificate the server is presenting, and reports its issuer, subject, validity dates, and whether the chain of trust back to a recognized root certificate authority is intact.

Browsers cache trust decisions and may already have loaded a page before a certificate expired or changed. A fresh server-side check reflects the certificate exactly as it is right now, catching problems your browser tab hasn't noticed yet.

Your server's certificate is normally signed by an intermediate certificate, which is itself signed by a trusted root. If the server fails to send the intermediate, browsers show a trust error even though your certificate itself is valid - this checker verifies the full chain, not just the leaf certificate.

Yes - the certificate's Subject Alternative Names (SAN) list is read directly from the certificate, so if it was issued for *.yourdomain.com, every subdomain it actually covers is shown.

This checker connects on the standard HTTPS port (443), covering the overwhelming majority of production websites - the certificate itself is unaffected by this tool's scope and would report identically wherever it's served.

A self-signed certificate has the same entity as both issuer and subject, rather than a trusted certificate authority. Browsers show a security warning for these unless manually trusted - common for internal/development environments, not appropriate for a public production site.

Yes - the certificate's signature algorithm (e.g. SHA-256 vs. the deprecated SHA-1) is read directly from the certificate data and reported, since SHA-1-signed certificates are no longer trusted by modern browsers.

This tool examines the certificate itself (issuer, validity, chain). The TLS Version Checker instead tests which TLS protocol versions your server is willing to negotiate a connection with - related but distinct aspects of your HTTPS setup.