Certline opens a TLS connection to a hostname you give it and reads the certificate the server actually presents. It reports what was sent, field by field — and whether the server sent the intermediate. It answers when you ask, and forgets.
No account. Nothing saved. No email, no alerts, no scheduled re-checks.
One input, one report. Certline is a diagnostic, not a dashboard.
A single hostname such as api.example.com. Certline checks only the name you typed — it never scans ranges or enumerates subdomains.
It connects on port 443 and reads the peer certificate from the TLS session itself — the server's leaf certificate and anything it sent with it.
Expiry date and days remaining, who issued it, every hostname it covers, and whether the chain is complete. If the server sent nothing, the report says so.
The point is the chain, not just the date. A certificate can be valid and the site still break, because the server sent the leaf without its intermediate — desktop browsers paper over it from cache, and mobile clients do not.
Certline reports what the server presented — not what your browser cached, not what you assume. If a field is absent, it says absent.
Check a hostname