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 a--s.ch
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- a--s.ch
- Valid from
- Jun 10, 2026
- Valid until
- Sep 8, 2026 (44 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 0522A203B6F53FFD991BC2D24A9201C9E49C
- SHA-256 fingerprint
- 9F:0D:7E:FC:53:45:0F:C7:A7:6C:C1:F4:26:FE:2F:54:05:75:C0:F4:3B:68:B2:B5:02:36:72:92:FB:7B:AB:02
- 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 Jul 26, 2026.
Never get surprised by a--s.ch's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch a--s.ch 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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