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 as-t.fr
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- www.as-t.fr
- Valid from
- Aug 23, 2026
- Valid until
- Nov 21, 2026 (35 days remaining)
- Public key
- RSA 4096-bit
- Serial
- 050B3930C3A5385B6C374C2907F344F5ADBE
- SHA-256 fingerprint
- 50:DF:18:66:55:12:B7:37:3E:62:74:0D:14:4C:59:76:EF:18:DB:D0:A9:A9:3F:8C:B4:79:F1:40:11:56:1E:71
- Chain
- YR2 → Root YR → ISRG Root X1
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 18, 2026.
Never get surprised by as-t.fr's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch as-t.fr 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.
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