SSL Certificate Checker

Read and analyze the TLS certificate a server presents.

Hostname

Connects to port 443 and reads the TLS certificate presented by the server.

What Is a SSL Certificate Checker?

The SSL Certificate Checker connects to a hostname on port 443, reads the TLS certificate it presents, and displays details including the issuer, validity dates, key type, signature algorithm, serial number, fingerprint, subject alternative names, and the full trust chain. It also indicates whether the certificate is currently within its validity window and whether the chain is trusted by the system. This free online security tool is useful for SSL certificate checker, TLS certificate checker, HTTPS certificate checker. Common use cases include checking certificate issuer, expiration, SANs, fingerprints, key information, and TLS configuration. It is designed for quick browser-based analysis and development workflows. Security checks are signals rather than guarantees, so production systems should also be validated against current standards and their specific threat model.

How to Use This SSL Certificate Checker

1
Enter the hostnameType the domain without unnecessary URL components.
2
Run the checkThe tool connects to the host over TLS on port 443.
3
Review certificate datesCheck the issue and expiration times.
4
Inspect the chainReview issuer, SANs, fingerprints, and trust information where available.
5
Plan renewalReplace or renew certificates before expiration to avoid HTTPS outages.

Frequently Asked Questions

Yes. The tool opens a real TLS connection on port 443 to fetch the certificate presented by the server. It uses a short timeout and strict SSRF protection.

It may mean the certificate is self-signed, expired, or not signed by a certificate authority the system recognizes. This can be normal for internal or testing servers.

Only the requested hostname is used to establish the connection. No other data is transmitted.

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