DNS
THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.3

o2.cz · 160.218.161.162:443

Verified
The certificate expires within 30 days.

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
C=CZ L=Praha O=O2 Czech Republic a.s. CN=*.o2.cz
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=Thawte TLS RSA CA G1
Valid from
2025-10-30T00:00:00+00:00
Expires
2026-10-29T23:59:59+00:00
Days remaining
24
Serial (hex)
04E0631AC22F8505841445F068FD771A
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.o2.cz, DNS:o2.cz

SHA-256 fingerprint

B5:44:E2:69:39:A1:29:8E:73:B8:85:9B:AD:FA:32:1A:C2:D3:91:7E:2C:77:3C:4A:8E:1C:2E:37:3C:95:39:22
Certificate extensions & PEM
authorityKeyIdentifier
A5:8C:FE:32:CC:EB:0F:2C:D4:19:C6:08:B8:00:24:88:5D:C3:C5:B7
subjectKeyIdentifier
C4:91:E6:4A:C8:88:99:B2:2F:ED:FB:58:5E:A8:C9:FF:54:58:ED:EA
subjectAltName
DNS:*.o2.cz, DNS:o2.cz
certificatePolicies
Policy: 2.23.140.1.2.2 CPS: http://www.digicert.com/CPS
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
crlDistributionPoints
Full Name: URI:http://cdp.thawte.com/ThawteTLSRSACAG1.crl
authorityInfoAccess
OCSP - URI:http://status.thawte.com CA Issuers - URI:http://cacerts.thawte.com/ThawteTLSRSACAG1.crt
basicConstraints
CA:FALSE
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9: 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77 Timestamp : Oct 30 11:49:08.018 2025 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:25:88:E0:A5:AF:44:C9:1A:47:AB:E7:DB: A7:77:4A:50:94:ED:89:7A:76:21:DD:4F:37:44:62:76: 98:8A:5A:88:02:20:73:FE:68:FA:C8:F0:72:44:71:5D: 39:13:51:AC:EC:B8:47:10:57:C6:08:C0:92:14:86:E6: 7C:F3:B9:C3:DB:58 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : C2:31:7E:57:45:19:A3:45:EE:7F:38:DE:B2:90:41:EB: C7:C2:21:5A:22:BF:7F:D5:B5:AD:76:9A:D9:0E:52:CD Timestamp : Oct 30 11:49:08.079 2025 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:69:CA:3E:F7:BF:2A:F9:55:A5:47:72:CE: 5A:01:2C:2A:12:81:4B:06:67:B7:37:88:F7:AD:10:9B: 79:86:9D:68:02:20:09:AB:54:9E:31:18:53:54:78:76: 29:9E:92:A5:9D:A9:07:19:72:B0:B7:41:74:00:72:01: A6:A9:51:78:B9:99 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 94:4E:43:87:FA:EC:C1:EF:81:F3:19:24:26:A8:18:65: 01:C7:D3:5F:38:02:01:3F:72:67:7D:55:37:2E:19:D8 Timestamp : Oct 30 11:49:08.096 2025 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:CF:1D:FE:76:20:C3:31:30:C7:B6:86: 93:5D:00:11:6F:B3:F3:2C:74:F4:9E:7C:D0:6A:E5:17: A1:54:D3:8D:36:02:21:00:EC:84:E2:B1:75:39:8D:8F: 2E:A2:C6:0E:54:54:4F:F1:0E:C0:51:D0:BA:AC:59:9F: 4F:E8:E9:27:DC:00:4F:F9
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-10-05T05:42:54+00:00

Server-presented chain · 1 additional certificate

Chain certificate 1

Subject
C=US O=DigiCert Inc OU=www.digicert.com CN=Thawte TLS RSA CA G1
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root G2
Valid from
2017-11-02T12:24:25+00:00
Expires
2027-11-02T12:24:25+00:00
Days remaining
393
Serial (hex)
090EE8C5DE5BFA62D2AE2FF7097C4857
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

4B:CC:5E:23:4F:E8:1E:DE:4E:AF:88:3A:A1:9C:31:33:5B:0B:26:E8:5E:06:6B:99:45:E4:CB:61:53:EB:20:C2
Certificate extensions & PEM
subjectKeyIdentifier
A5:8C:FE:32:CC:EB:0F:2C:D4:19:C6:08:B8:00:24:88:5D:C3:C5:B7
authorityKeyIdentifier
4E:22:54:20:18:95:E6:E3:6E:E6:0F:FA:FA:B9:12:ED:06:17:8F:39
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:TRUE, pathlen:0
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.com
crlDistributionPoints
Full Name: URI:http://crl3.digicert.com/DigiCertGlobalRootG2.crl
certificatePolicies
Policy: X509v3 Any Policy CPS: https://www.digicert.com/CPS
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

View certificate JSON

Registration / WHOIS →DNS records →