SSL certificate checker

Inspect the TLS certificate presented to us: who it is for, who issued it, when it expires, and fingerprints—without needing your browser’s trust store to agree first.

Enter a hostname (and optional port) to inspect the certificate chain presented to us.

What SSL / TLS inspection is for

TLS certificates bind public keys to names, expire on a schedule, and are issued by CAs (or your own PKI). Browsers warn users when something is wrong; operators want to know expiry, chain, SAN coverage, and issuer before that happens.

Common questions sound like: “Does this host present a valid cert for my domain?” “When does it expire?” “Who issued it?” This tool shows what certificate chain our client sees when connecting to the host and port you specify.

We connect with verification relaxed so you can still inspect misconfigured or expired certs (your browser might refuse entirely). Always treat production trust decisions with your real client settings and monitoring stack.

How this tool works

Short technical summary of what runs on our servers when you click the button.

TLS handshake from BuildSpace

We open a TLS socket, read the peer certificate (including chain when available), and return subject, issuer, validity window, fingerprints, and subject alternative names.

SNI and port

Hostname is used for Server Name Indication. Default port is 443; you can target other TLS ports if your service terminates TLS there.

Host allowlisting

The same public-host rules apply: we will not use this tool to probe private IP space or internal-only names.

More BuildSpace tools

All utilities run from our infrastructure with the same safety limits. No account required.

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