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

telecom.tw · 193.42.42.75:443

Verified

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

Subject
CN=telecom.tw
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-10-31T08:57:58+00:00
Expires
2027-01-29T08:57:57+00:00
Days remaining
88
Serial (hex)
0619CF7FAAD430A2DC7B70353015170508E8
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:telecom.tw, DNS:www.telecom.tw

SHA-256 fingerprint

AD:BE:8D:D4:81:7B:2A:CD:3F:09:63:BC:09:2A:C1:B0:37:4E:FF:EC:09:8D:EC:72:4F:C9:55:A9:0D:24:F6:E8
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
83:0B:24:79:6E:D4:3B:42:98:EC:FB:D9:47:44:1F:19:21:78:DA:FD
authorityKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
authorityInfoAccess
CA Issuers - URI:http://yr2.i.lencr.org/
subjectAltName
DNS:telecom.tw, DNS:www.telecom.tw
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/105.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 31 09:56:28.318 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:DB:66:2A:89:B0:3C:B0:33:31:EC:A6: B6:60:38:6E:D8:87:D4:64:95:F4:FA:DF:8B:2C:E8:36: FA:43:F6:BF:28:02:21:00:A9:AB:B9:07:16:4C:04:C0: E4:D0:0C:C7:13:FE:B4:9A:19:92:65:08:E6:FA:BF:85: 58:48:17:7F:3E:BF:0D:15 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1A:8B:9D:6B:8D:D7:91:D1:CD:05:49:ED:B6:03:55:D6: 06:B6:4F:AD:30:DB:71:FE:78:8F:0F:C7:C8:FB:C4:B1 Timestamp : Oct 31 09:56:29.740 2026 GMT Extensions: 00:00:05:00:10:85:C6:8B Signature : ecdsa-with-SHA256 30:44:02:20:71:18:B7:A8:8F:A4:59:CA:7F:68:4C:E2: CF:5A:B8:4D:7C:D3:06:90:3A:F5:BA:A0:2D:AD:E0:88: AB:73:CB:B5:02:20:3B:AA:10:C1:C3:BC:A5:5C:E8:42: 49:50:14:31:98:CF:F5:D4:EF:3B:D2:2D:38:48:7A:0F: E6:8F:C0:02:69:8A
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-01T13:57:04+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR2
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
671
Serial (hex)
4EBD24947E24D394802D84A52FD5B319
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

23:8B:85:A0:09:9C:65:B9:70:47:7D:57:24:F1:A1:D4:75:CE:50:58:CF:FE:4E:FA:87:33:89:9B:DB:86:3C:47
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
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
2132
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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