SSL/TLS Certificate Lookup

Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted

SSL/TLS Certificate for ondrej-fiala.cz

Valid
Issued by (CA)
Let's Encrypt
Subject
ondrej-fiala.cz
Valid from
Jun 17, 2026
Valid until
Sep 15, 2026 (53 days remaining)
Public key
EC 256-bit
Serial
063F69953307CB85160A5FF308CBC02047B6
SHA-256 fingerprint
58:9B:27:4C:94:FF:AC:1C:BB:25:92:EE:C2:E6:04:2E:AF:AF:F3:C0:8D:47:07:10:B7:53:25:35:69:54:07:20
Chain
YE1 → Root YE → ISRG Root X2 → ISRG Root X1
Subject Alternative Names (2)
*.ondrej-fiala.cz, ondrej-fiala.cz

Certificate Authority Authorization (CAA)

No CAA policy is published for this domain — any certificate authority may issue for it.

Never get surprised by ondrej-fiala.cz's certificate expiring

This is today's certificate. Turn on monitoring and we'll watch ondrej-fiala.cz continuously, notifying you the moment anything moves across all three signals:

Uptime

We visit the site from multiple regions worldwide and email you within minutes if it goes down, with a per-region breakdown so a real outage stands out from a regional blip.

DNS changes

We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.

TLS certificate

We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.

Monitor this certificate free

Free for your first domain: uptime, DNS, and certificate together. No credit card.