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.uiw.pl · 80.87.33.196:443

Verified

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

Subject
CN=mail.uiw.pl
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-10-27T04:51:13+00:00
Expires
2027-01-25T04:51:12+00:00
Days remaining
83
Serial (hex)
0693983C24EA238643C260F785E5410945F8
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:mail.uiw.pl, DNS:poczta.uiw.pl

SHA-256 fingerprint

B1:D2:F1:A1:22:C6:39:C0:B0:BE:9E:E3:24:DF:45:C1:CF:6F:4F:10:69:FB:69:28:A9:8D:B0:12:A5:B3:24:0C
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
5B:97:F0:26:79:5D:E0:19:65:82:07:66:73:35:E5:18:74:39:FD:7A
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.uiw.pl, DNS:poczta.uiw.pl
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/121.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1C:9F:68:2C:E9:FA:F0:45:69:50:F8:1B:96:8A:87:DD: DB:32:10:D8:4C:E6:C8:B2:E3:82:52:4A:C4:CF:59:9F Timestamp : Oct 27 05:49:43.409 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:4C:40:E7:2B:9F:B3:06:36:50:CA:79:42: 34:8A:61:C0:8C:6C:5A:B5:71:7A:88:35:56:47:CD:8E: 88:BF:85:AA:02:21:00:CF:07:84:C7:40:50:78:E6:19: A9:8D:F8:A4:D7:7D:F7:6C:00:96:D3:D4:3D:46:2A:3B: 38:43:F5:39:FC:ED:36 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 8E:CA:47:0B:AC:DE:6A:F3:A2:06:B0:A4:7A:84:B7:46: FE:1F:C6:BF:95:3E:25:E6:9B:4E:E4:02:48:F3:C6:E8 Timestamp : Oct 27 05:49:43.973 2026 GMT Extensions: 00:00:05:00:2F:8D:8B:22 Signature : ecdsa-with-SHA256 30:44:02:20:6A:3A:3E:D5:AC:C2:60:00:4C:AA:C3:AC: 1E:40:9A:7E:EC:2E:06:3F:57:05:A7:05:38:8C:01:25: 8E:9F:DC:F2:02:20:10:16:2C:61:47:62:54:72:86:45: 5E:22:B3:E5:91:D3:B1:0A:5B:CF:53:F1:AF:EE:1D:66: EE:16:86:99:83:54
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-11-03T03:28:39+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
669
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-----
MIIE2zCCAsOgAwIBAgIRAKICU/FfJpHAXcHOE7m8yk4wDQYJKoZIhvcNAQELBQAw
LjELMAkGA1UEBhMCVVMxDTALBgNVBAoTBElTUkcxEDAOBgNVBAMTB1Jvb3QgWVIw
HhcNMjUwOTAzMDAwMDAwWhcNMjgwOTAyMjM1OTU5WjAzMQswCQYDVQQGEwJVUzEW
MBQGA1UEChMNTGV0J3MgRW5jcnlwdDEMMAoGA1UEAxMDWVIxMIIBIjANBgkqhkiG
9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoVi8X2xCYgMXvJxNPKp/oF13UMgmPABB07VC
LNDtoXmt9luEZNJSBV10VyT1Pz6LD8Zq1d2gc43WNl1AdRrj4sEnazbOiz0nPpmG
Bp2hui49oZtDIY6wdKeZAi5BbNU20CH6RSBBMLSQ9cXrH8dxdv4PAJ45ssGML68U
SE3BsjC2a6cAN9L5CgXVIQi5tfNiTPoFZZ3S0OlXqLmmtdV95udWAb5b6e/F49Di
CsH0Y00Ag72BVIb1hzynmKe+X0mERBTtsb3BwmpV9ipeBjMLoR/D9cHxHQCWoi5l
TmXwY015J5rGelz1nZjJuxc2kioaX29XJBnhMkP531rSdG5uMwIDAQABo4HuMIHr
MA4GA1UdDwEB/wQEAwIBhjATBgNVHSUEDDAKBggrBgEFBQcDATASBgNVHRMBAf8E
CDAGAQH/AgEAMB0GA1UdDgQWBBQfLzW+RhSCzUCxrnksVXj699Ro+zAfBgNVHSME
GDAWgBTe51tg0CJtQCh9Pw0B/qS1UrRRlDAyBggrBgEFBQcBAQQmMCQwIgYIKwYB
BQUHMAKGFmh0dHA6Ly95ci5pLmxlbmNyLm9yZy8wEwYDVR0gBAwwCjAIBgZngQwB
AgEwJwYDVR0fBCAwHjAcoBqgGIYWaHR0cDovL3lyLmMubGVuY3Iub3JnLzANBgkq
hkiG9w0BAQsFAAOCAgEA0+zvMq3kHig1ddTmmm+RibTr9/RpX7k4buanMMRqbV/y
IvP82zAHN3mvaw+cASuVsdpd0ikjhr4hnhJQLQOzOp2ccKrsdGOAgo0vddeISFAq
EWEV4lmUM3vFF796up+bSgmJ1u6RupDCMxDgF8M3eLvGuj6L0lu3zkQ0KuQLnKxL
tB0oQqn1Idg5CuuGpMvQzk29Pa3D/qHurc0EIM9SxukQuJqq63lxsYyRQFU8yMBO
hq1w5LbfaWNRrz1uklOfI/pYkAb2E2MTZrAMQkBIE2S8Jt1F8gRc96o/xOsrgvSk
a84AisX6xq1lz1Z7jGvrnXc4TMcjxZTjiTaihcYI1JIXZiLtEMSCa5l3cu8YWd6z
dLRQlqRdclVjuQfNHawRJ6GWlkK0QJosivTKwdBw3KxEtzGo8yMHERbsy57gP1UX
HOMcmZYQC0gtyR3SxfenIM/MxC3Ia2Ypab/kQ/CTnlIn2KQ5JUC6NYrGCbhFN9bp
5lKJStEwCUnLpntcrXk5XVDCNv/5RyWpRThkGOV7GetKkQ0qAY8hCzWK6oqnAhDZ
cjlYVdWfqOw3DIOX6EDNBgAqHarRVxyF9QZdOaXSyPJ0ueD2BYJEBgaCGQ8rAaU/
Qc123V5LTXDZW4CcsPBDyhy4v+c8hClAyw/IkJlfBqxB9D+/wvIMHgECZ4ptP6o=
-----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
2130
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

Registration / WHOIS →DNS records →