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

TLSv1.2

fns1.42.pl · 79.98.145.34:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. Peer certificate CN=`freedns.42.pl' did not match expected CN=`fns1.42.pl'
The certificate expires within 30 days.

Certificate verification failed

Subject
CN=freedns.42.pl
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-08-01T01:44:03+00:00
Expires
2026-10-30T01:44:02+00:00
Days remaining
26
Serial (hex)
06CA73775D7056F50BEDC5D8F9E79815DC34
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:freedns.42.pl

SHA-256 fingerprint

DC:7C:7E:30:B7:A8:5C:61:20:19:A5:3E:11:9F:BA:2D:66:73:62:B1:C4:3F:AA:3A:85:7C:9C:6D:AB:4A:BC:64
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
21:B8:91:C4:DA:98:ED:56:9C:8E:75:66:5B:99:7B:FC:C7:3A:AD:11
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:freedns.42.pl
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/53.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 94:4E:43:87:FA:EC:C1:EF:81:F3:19:24:26:A8:18:65: 01:C7:D3:5F:38:02:01:3F:72:67:7D:55:37:2E:19:D8 Timestamp : Aug 1 02:42:33.573 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:F7:BD:2F:2A:EB:51:8A:E3:B2:80:DB: D3:70:7F:14:E3:FC:3A:75:52:F2:9C:DD:9D:DD:2F:48: 48:E6:1C:4E:DF:02:20:23:22:93:88:39:DF:20:77:DA: F2:16:82:AD:9B:B7:19:4C:EA:56:30:0D:EE:F4:6C:E9: B5:03:36:13:28:C6:10 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 26:E3:64:6E:58:69:21:23:BC:34:3F:47:24:35:9B:37: 92:CD:24:5A:88:D8:15:D3:93:33:FD:99:18:AB:47:23 Timestamp : Aug 1 02:42:32.526 2026 GMT Extensions: 00:00:05:00:2F:AF:54:13 Signature : ecdsa-with-SHA256 30:45:02:21:00:B9:95:D9:26:B5:BD:5B:F4:2A:5B:28: 45:37:F8:F9:25:E4:82:82:56:CA:E3:52:D6:4D:12:BF: 95:F9:B7:F7:01:02:20:4C:A7:27:92:75:34:8A:72:01: EA:FD:B9:D1:D8:7F:91:CB:0E:9A:B1:7E:54:23:9D:A2: F7:CB:74:9F:8E:63:79
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES256-GCM-SHA384 · Checked 2026-10-03T05:45:54+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
700
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
2161
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 →