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 a1-immo.de

Valid
Issued by (CA)
Let's Encrypt
Subject
a1-immo.de
Valid from
Oct 11, 2026
Valid until
Jan 9, 2027 (68 days remaining)
Public key
EC 256-bit
Serial
0602B8C8DED354AEAD1D9BCC5D6CEFFD0ABC
SHA-256 fingerprint
7E:2A:CF:7E:6D:B4:A4:A4:83:70:A7:37:BF:1D:36:4B:4D:44:B6:9D:84:9C:36:6E:4B:54:72:FB:F5:F9:37:E1
Chain
YE2 → Root YE → ISRG Root X2 → ISRG Root X1
Subject Alternative Names (2)
a1-immo.de, www.a1-immo.de

Certificate Authority Authorization (CAA)

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

This certificate has been served since Sep 25, 2026.

Never get surprised by a1-immo.de's certificate expiring

This is today's certificate. Turn on monitoring and we'll watch a1-immo.de continuously, notifying you the moment anything moves across all three signals:

Certificate monitor showing the issuer, expiry date, chain status, fingerprint, covered names, and a history of a rotation and an expiry warning

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, CNAME, TXT 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.