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

i-system.hk · 182.173.76.91:443

Verified

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

Subject
CN=i-system.hk
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-09-16T16:42:54+00:00
Expires
2026-12-15T16:42:53+00:00
Days remaining
67
Serial (hex)
061917DDA6B2E5B95C522196EA5BDB47CF76
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.i-system.hk, DNS:*.xn--blqt99bv5qu7f.xn--j6w193g, DNS:i-system.hk, DNS:xn--blqt99bv5qu7f.xn--j6w193g

SHA-256 fingerprint

D3:84:FD:56:05:26:EB:D7:4F:93:F2:4B:5D:49:EA:BC:E0:53:AC:7A:FE:9B:7B:A5:B8:5E:B5:8B:C8:EF:33:A8
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
52:09:4F:73:84:9A:9F:EA:FB:0C:73:73:66:B1:68:C2:74:CB:59:27
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:*.i-system.hk, DNS:*.xn--blqt99bv5qu7f.xn--j6w193g, DNS:i-system.hk, DNS:xn--blqt99bv5qu7f.xn--j6w193g
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/119.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 6C:FE:50:19:43:A8:5E:A9:16:BC:52:D1:33:E4:DC:C9: 1E:F1:41:1C:7D:25:84:20:D1:73:80:9E:18:18:EB:3A Timestamp : Sep 16 17:41:24.607 2026 GMT Extensions: 00:00:05:00:36:DE:DC:94 Signature : ecdsa-with-SHA256 30:46:02:21:00:AB:4C:D4:86:D5:1D:C8:A7:68:C1:8F: 3A:41:D8:E3:56:85:46:8E:FC:5E:A4:8F:6C:CA:BC:B7: C6:30:A3:D7:C6:02:21:00:AE:BB:D6:C2:03:27:84:1E: 6D:F6:3D:1F:42:A7:0B:42:B3:CD:EF:99:3D:6E:DE:17: 8F:7E:D5:A2:79:1B:46:8E Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D8:09:55:3B:94:4F:7A:FF:C8:16:19:6F:94:4F:85:AB: B0:F8:FC:5E:87:55:26:0F:15:D1:2E:72:BB:45:4B:14 Timestamp : Sep 16 17:41:26.413 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:CC:F1:3C:ED:82:09:02:CA:14:C3:30: AD:B9:B3:44:86:59:C4:13:45:F1:6B:F5:B0:75:DE:DF: D0:D8:B7:6D:50:02:21:00:8D:B3:30:4C:5E:6C:EB:22: 04:0D:E7:26:ED:7B:46:C2:20:C8:86:00:F4:FD:A4:7E: 00:A7:92:C5:DE:D6:E4:06
-----BEGIN CERTIFICATE-----
MIIFQjCCBCqgAwIBAgISBhkX3aay5blcUiGW6lvbR892MA0GCSqGSIb3DQEBCwUA
MDMxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQwwCgYDVQQD
EwNZUjEwHhcNMjYwOTE2MTY0MjU0WhcNMjYxMjE1MTY0MjUzWjAWMRQwEgYDVQQD
EwtpLXN5c3RlbS5oazCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMIj
35V5YguoNNXfWncrmhtjpv6lkjliv69r5ekcIKRsFCEWWkwn2EQb00DsQyDk8IcH
LZAy43oz6kZwt9WDB/YbDAC0xy2kL8ePoJNi8ehmuxNPbpzoPe3z4FeAHkzrXF7R
uLqy+MnEe7z5CoLFf1/kLr1Qk4PHHnoGeLasx1qqo9WhgoY1UCSSZ8heBHpdAJ85
wWf4J1aN59N6KddXAZa13rDK9KPTvAaksfYl/OS5t8yCM3qUh5IMlAb3gpRfi001
EESQug9KjuBwbMJDOYrAPTBskFhLrWExPOCpIKhCX1vzwceq20O++e4rqe3YJO/8
a3NMaK4VqmtOfpr5fHMCAwEAAaOCAmswggJnMA4GA1UdDwEB/wQEAwIFoDATBgNV
HSUEDDAKBggrBgEFBQcDATAMBgNVHRMBAf8EAjAAMB0GA1UdDgQWBBRSCU9zhJqf
6vsMc3NmsWjCdMtZJzAfBgNVHSMEGDAWgBQfLzW+RhSCzUCxrnksVXj699Ro+zAz
BggrBgEFBQcBAQQnMCUwIwYIKwYBBQUHMAKGF2h0dHA6Ly95cjEuaS5sZW5jci5v
cmcvMGUGA1UdEQReMFyCDSouaS1zeXN0ZW0uaGuCHyoueG4tLWJscXQ5OWJ2NXF1
N2YueG4tLWo2dzE5M2eCC2ktc3lzdGVtLmhrgh14bi0tYmxxdDk5YnY1cXU3Zi54
bi0tajZ3MTkzZzATBgNVHSAEDDAKMAgGBmeBDAECATAvBgNVHR8EKDAmMCSgIqAg
hh5odHRwOi8veXIxLmMubGVuY3Iub3JnLzExOS5jcmwwggEOBgorBgEEAdZ5AgQC
BIH/BIH8APoAfwBs/lAZQ6heqRa8UtEz5NzJHvFBHH0lhCDRc4CeGBjrOgAAAaCr
Tx//AAgAAAUANt7clAQDAEgwRgIhAKtM1IbVHcinaMGPOkHY41aFRo78XqSPbMq8
t8Ywo9fGAiEArrvWwgMnhB5t9j0fQqcLQrPN75k9bt4Xj37VonkbRo4AdwDYCVU7
lE96/8gWGW+UT4WrsPj8XodVJg8V0S5yu0VLFAAAAaCrTycNAAAEAwBIMEYCIQDM
8TztggkCyhTDMK25s0SGWcQTRfFr9bB13t/Q2LdtUAIhAI2zMExebOsiBA3nJu17
RsIgyIYA9P2kfgCnksXe1uQGMA0GCSqGSIb3DQEBCwUAA4IBAQB2KcEmaxEfWwhz
eUJ8BPynNgMsqqmYxVE8qZMvzoAA0/TnKvh01t1g5t85RO6T8rpg3gMTDPK4AS5C
4UYdp6yJEBSsILInxuj7LWbCLBQkv6n9owd4MlOhP19XbNHqycRVcsttqhHvbcTe
OgAc0skguAbni3cCWFlhXfwTQwO9w+iTB7fSyAZRJOjeQr2w1wWPB9B8/4gs4lkF
3y1fPCfMCGjIhjRuQ+6o3+YDTLc+0D+tmz22O2xvilhG8lVc+SJwEWAqbn+sdZ9b
27Ce2/s9Ydg5c/BFqWInstkLgO8Ghf+8EqtsiNOkprAMu5b7mC3JXP/eCRl7Jbga
AzvJBD3x
-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-10-08T19:13:48+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
695
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
2156
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 →