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

mail.tele3.cz · 81.0.217.77:443

Verified

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

Subject
CN=mail.tele3.cz
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-10-17T12:28:35+00:00
Expires
2027-01-15T12:28:34+00:00
Days remaining
68
Serial (hex)
067A6C9A8A1001EA547BDA9AD52AF84F18C1
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:mail.tele3.cz

SHA-256 fingerprint

A0:2D:C3:FA:9C:E7:E1:AA:64:36:8D:08:C1:21:49:91:81:6B:CF:61:3A:81:94:B1:4C:3C:42:07:51:35:3C:AE
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
C3:5D:93:A9:8A:20:0A:91:A6:A7:A5:FF:B2:DF:5F:C1:AF:0A:3E:03
authorityKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityInfoAccess
CA Issuers - URI:http://yr1.i.lencr.org/
subjectAltName
DNS:mail.tele3.cz
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/66.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 4C:63:DC:98:E5:9C:1D:AB:88:F6:1E:8A:3D:DE:AE:8F: AB:44:A3:37:7B:5F:9B:94:C3:FB:A1:9C:FC:C1:BE:26 Timestamp : Oct 17 13:27:05.545 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:FB:50:05:57:55:80:F1:51:51:44:F7: 38:2A:19:A9:8F:D1:02:F2:8D:B4:C9:65:C9:06:93:82: E7:BB:1A:AC:29:02:20:2D:E7:0E:76:32:E8:C2:6A:9B: 2E:C2:85:D3:52:FE:AD:27:F1:2A:87:73:62:89:03:D0: 05:69:74:2D:8F:6A:56 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 59:6E:6C:33:86:94:B2:59:72:A2:56:C8:A0:E8:DD:90: 4A:76:E8:08:3D:DA:87:3B:01:08:38:28:14:3C:EE:59 Timestamp : Oct 17 13:27:07.767 2026 GMT Extensions: 00:00:05:00:0F:25:E6:50 Signature : ecdsa-with-SHA256 30:44:02:20:65:DE:7D:5A:FC:52:D8:D6:D5:F4:1D:E9: 87:3E:E5:2A:9E:0E:F6:71:AB:63:5F:C5:0F:80:F8:A8: 0C:AB:15:92:02:20:0F:27:55:B0:E8:D2:C1:95:2D:D2: 1A:54:E3:E2:27:E4:B0:A2:79:8A:F8:58:E4:AD:B6:77: 97:AC:82:26:2B:BF
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-07T18:08:42+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR1
Issuer
C=US O=ISRG CN=Root YR
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
665
Serial (hex)
A20253F15F2691C05DC1CE13B9BCCA4E
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

13:94:96:34:D9:9C:D6:FD:6A:A8:0B:C0:34:FE:FA:CC:EB:19:69:FE:EF:98:65:86:71:3E:CD:BB:05:75:8D:3F
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityInfoAccess
CA Issuers - URI:http://yr.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YR
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X1
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2126
Serial (hex)
F24B6D17F9D9AD7CB1C9FEA78782699F
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

07:26:39:D0:B1:40:D5:BF:FA:E1:6A:D9:C3:F6:CC:60:86:04:06:21:F5:1E:E6:1A:6D:46:A8:91:5C:07:CF:76
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityKeyIdentifier
79:B4:59:E6:7B:B6:E5:E4:01:73:80:08:88:C8:1A:58:F6:E9:9B:6E
authorityInfoAccess
CA Issuers - URI:http://x1.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x1.c.lencr.org/ 
-----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

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