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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

k.io · 151.252.2.100:443

Verified

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

Subject
CN=k.io
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-09-14T08:13:24+00:00
Expires
2026-12-13T08:13:23+00:00
Days remaining
50
Serial (hex)
067A227D971B0F74D199FA5D8BBEFEC00504
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:k.io

SHA-256 fingerprint

70:F2:D7:60:FC:1A:72:7A:F4:45:E2:1B:00:E5:23:A2:81:08:AC:3A:E6:84:79:2A:9C:A5:2E:95:77:BF:38:1A
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
8A:31:26:60:25:CB:FA:C8:01:AF:5B:70:DD:91:79:E4:A0:1C:94:87
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:k.io
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/5.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 14 09:11:57.606 2026 GMT Extensions: 00:00:05:00:34:E1:76:23 Signature : ecdsa-with-SHA256 30:45:02:21:00:DF:64:D0:72:20:8B:1E:4C:BC:01:F4: 71:B0:93:2B:9F:D7:83:6B:D0:3A:F1:D2:ED:D7:A5:B5: 73:38:C2:2D:87:02:20:7D:E6:BC:88:32:50:57:75:6E: E7:1A:B0:53:7A:A3:88:FD:60:C4:21:15:AB:E0:72:4E: 0E:7C:84:49:A7:CD:B6 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : C8:A3:C4:7F:C7:B3:AD:B9:35:6B:01:3F:6A:7A:12:6D: E3:3A:4E:43:A5:C6:46:F9:97:AD:39:75:99:1D:CF:9A Timestamp : Sep 14 09:11:58.177 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:7C:42:34:3A:40:B1:7A:DB:8D:1A:04:A7: BA:6D:07:1B:9F:1C:A9:08:75:60:92:F6:51:31:1A:B9: 52:67:F7:13:02:20:6D:5C:A8:32:19:64:78:B3:8E:72: B3:30:E7:B9:39:21:26:E9:B2:D7:AF:93:C9:90:F9:C9: 79:29:33:7C:81:E5
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-10-23T12:49:06+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
680
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
2141
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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