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

seimitsu.com · 198.49.23.145:443

Verified

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

Subject
CN=seimitsu.com
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-10-23T01:22:49+00:00
Expires
2027-01-21T01:22:48+00:00
Days remaining
78
Serial (hex)
05FD9A49CCB72DCA23DBBC0A50AEB91EDED6
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:seimitsu.com

SHA-256 fingerprint

BA:71:F8:EF:4B:F5:9B:FC:A1:09:AC:A5:27:20:76:AB:A5:4E:F9:D7:E6:E1:1F:99:59:1D:03:B6:12:ED:6F:0C
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
0F:BF:74:71:62:43:C8:0F:D3:B9:12:8F:FC:9C:72:8C:2E:93:A5:5E
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:seimitsu.com
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/87.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 4C:63:DC:98:E5:9C:1D:AB:88:F6:1E:8A:3D:DE:AE:8F: AB:44:A3:37:7B:5F:9B:94:C3:FB:A1:9C:FC:C1:BE:26 Timestamp : Oct 23 02:21:19.701 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:61:5D:65:A4:F7:C5:76:16:AB:5F:AC:0A: 5E:2F:74:ED:A9:C4:EE:54:11:1D:67:CD:CA:61:12:25: CE:F6:83:EA:02:21:00:B2:5E:6F:67:55:79:CF:8F:FC: 44:7E:D5:02:61:B9:CD:AD:E2:25:CC:CF:40:79:A7:79: 35:9B:CF:8F:19:33:D3 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 59:6E:6C:33:86:94:B2:59:72:A2:56:C8:A0:E8:DD:90: 4A:76:E8:08:3D:DA:87:3B:01:08:38:28:14:3C:EE:59 Timestamp : Oct 23 02:21:19.849 2026 GMT Extensions: 00:00:05:00:12:F8:4B:57 Signature : ecdsa-with-SHA256 30:45:02:20:20:C7:80:D2:3D:02:22:11:EA:1A:76:DE: C6:6A:1F:A6:72:EF:31:1C:E6:10:3F:6D:81:F8:82:06: 5B:3A:C2:FA:02:21:00:84:4F:5B:F7:57:52:F1:47:AD: 5D:4F:45:D9:A6:79:60:85:60:F6:30:10:19:19:64:D6: 71:2A:06:19:C8:82:53
-----BEGIN CERTIFICATE-----
MIIE8jCCA9qgAwIBAgISBf2aScy3Lcoj27wKUK65Ht7WMA0GCSqGSIb3DQEBCwUA
MDMxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQwwCgYDVQQD
EwNZUjIwHhcNMjYxMDIzMDEyMjQ5WhcNMjcwMTIxMDEyMjQ4WjAXMRUwEwYDVQQD
EwxzZWltaXRzdS5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCA
Xi4IgbuNrlK0eqQhuftk7b26BoD46wdEJIWoH0c0qB5MdaMka65yH4fYjufuvxxm
mC/gPp7e2X8FYGdA1rQCpVzTDCXjqoJtVG2ewo8G4CisqrmpVu42jrRP93XX1NKR
KEtGq8XCNyMOhJhZsB/ilttkXbVrxg9zmb2g50P1mgXuRjarwtqT1hoBaU7FXPQt
qUro9xQJjak5SE4DGkZVCPHzil+6OGjw82uz0VTOvbDmVV0vGF//u0OLRwDJjixp
XBmwh9BNDaIO/0xYwbiT7PHcRsFtb/JV58hXtdji8gMqS27a7KHfmIgOqx91XUsa
Qpp7JzlJzwtz931VaNGdAgMBAAGjggIaMIICFjAOBgNVHQ8BAf8EBAMCBaAwEwYD
VR0lBAwwCgYIKwYBBQUHAwEwDAYDVR0TAQH/BAIwADAdBgNVHQ4EFgQUD790cWJD
yA/TuRKP/JxyjC6TpV4wHwYDVR0jBBgwFoAUQBUtJnntMiCe35pyHdYyH4EMgQww
MwYIKwYBBQUHAQEEJzAlMCMGCCsGAQUFBzAChhdodHRwOi8veXIyLmkubGVuY3Iu
b3JnLzAXBgNVHREEEDAOggxzZWltaXRzdS5jb20wEwYDVR0gBAwwCjAIBgZngQwB
AgEwLgYDVR0fBCcwJTAjoCGgH4YdaHR0cDovL3lyMi5jLmxlbmNyLm9yZy84Ny5j
cmwwggEMBgorBgEEAdZ5AgQCBIH9BIH6APgAdgBMY9yY5Zwdq4j2Hoo93q6Pq0Sj
N3tfm5TD+6Gc/MG+JgAAAaFmkA/VAAAEAwBHMEUCIGFdZaT3xXYWq1+sCl4vdO2p
xO5UER1nzcphEiXO9oPqAiEAsl5vZ1V5z4/8RH7VAmG5za3iJczPQHmneTWbz48Z
M9MAfgBZbmwzhpSyWXKiVsig6N2QSnboCD3ahzsBCDgoFDzuWQAAAaFmkBBpAAgA
AAUAEvhLVwQDAEcwRQIgIMeA0j0CIhHqGnbexmofpnLvMRzmED9tgfiCBls6wvoC
IQCET1v3V1LxR61dT0XZpnlghWD2MBAZGWTWcSoGGciCUzANBgkqhkiG9w0BAQsF
AAOCAQEAnDduAgPwZi9cQ1l6Xx9GMhm2fmnKNjRo7eL8D/1LT1P2FUtpU3SeWVXn
VVYS6YG0DbvZwIhiAzzMcm6EvK9zXbtzL64yjL0h5gj6p+u0kypVACU94keq6O11
pMIOth8USe3etHUX5QSQ0weeIu3J33il9l9u2oHD5QHGqBqtjNhfozb+Fm3gCiaE
lriIirzHO8efcTyGPI14GAxspdvKoTISKIlksG5ulf6tAGFyW0BDPGbSwcTvmneM
DmRda761AQrL+s4YDybLLNpuKnZzMDJq4ZJIge1EmnVkoDJIhC3kSGp0G95VpQe3
4XBHlnADU0ndeKjhukEtFtUE/Cy4IA==
-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-11-03T23:24:13+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
669
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
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

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