SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
office.com
SSL/TLS Certificate
SSL/TLS Certificate for office.com
Valid- Issued by (CA)
- Microsoft Corporation
- Subject
- m365.cloud.microsoft
- Valid from
- Jun 2, 2026
- Valid until
- Nov 29, 2026 (112 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 490040EFF66E166E3F9CA9DF1800000040EFF6
- SHA-256 fingerprint
- 23:55:FB:8B:7C:A8:22:27:42:66:DD:9B:5E:BF:FF:E9:86:79:E0:F2:7F:3D:03:B5:42:60:75:8C:53:BD:F8:4F
- Chain
- Microsoft TLS G2 RSA CA OCSP 10 → Microsoft TLS RSA Root G2 → DigiCert Global Root G2
Certificate Authority Authorization (CAA)
CAA restricts issuance to digicert.com, dtrust.de, entrust.net, globalsign.com, microsoft.com; we couldn't map the serving CA (Microsoft Corporation) to one of these identifiers.
This certificate has been served since Jul 19, 2026.
Never get surprised by office.com's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch office.com 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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