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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

servers.guru · 104.21.35.80:443

Verified

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

Subject
CN=servers.guru
Issuer
C=US O=Let's Encrypt CN=YE1
Valid from
2026-09-15T11:17:20+00:00
Expires
2026-12-14T11:17:19+00:00
Days remaining
79
Serial (hex)
06BD7D68EE51CE195E59FE3817CFB9BED018
Signature
ecdsa-with-SHA384
Public key
EC 256 prime256v1

Subject alternative names (SAN)

DNS:redirect.mail.servers.guru, DNS:servers.guru

SHA-256 fingerprint

00:8B:E5:FE:70:C4:3F:FB:82:4D:C9:09:98:87:F5:AE:B7:13:CA:A6:50:7A:ED:7B:17:4B:4D:FB:F0:84:0A:09
Certificate extensions & PEM
keyUsage
Digital Signature
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
07:F0:43:9D:3F:95:84:70:9E:2A:A4:E1:A1:A2:B8:A6:EA:D2:E8:DF
authorityKeyIdentifier
BB:20:CA:47:0B:FE:D7:E5:9C:F9:8F:09:2A:A3:8C:37:45:B1:BC:D8
authorityInfoAccess
CA Issuers - URI:http://ye1.i.lencr.org/
subjectAltName
DNS:redirect.mail.servers.guru, DNS:servers.guru
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://ye1.c.lencr.org/25.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 : Sep 15 12:15:51.061 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:96:9C:E7:58:78:45:4D:AE:BA:BB:6F: E7:83:93:ED:F1:55:7C:F1:D2:EF:36:B2:AB:4D:C4:64: 79:C1:81:D6:B8:02:20:62:0C:7E:AE:12:FE:CB:CE:04: AD:E6:7A:4C:30:9C:38:7B:33:C0:82:D5:56:AB:7E:89: 30:58:5E:A3:66:81:47 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 46:AF:86:3D:3B:3E:E5:9F:A5:77:DE:A8:24:5D:36:B0: D9:ED:22:A2:23:F4:61:77:41:22:94:52:EE:95:50:5F Timestamp : Sep 15 12:15:51.152 2026 GMT Extensions: 00:00:05:00:2E:F5:0E:E2 Signature : ecdsa-with-SHA256 30:46:02:21:00:D4:1F:CD:B5:0D:60:B6:78:25:C2:8E: AE:48:AB:C1:39:E3:A6:0A:CB:07:05:5C:08:5E:AC:3D: EA:90:92:B4:F8:02:21:00:D9:1F:28:72:01:34:F4:08: B6:10:3E:F8:DA:98:2E:16:67:04:A2:48:36:45:55:49: C4:E2:23:78:38:07:7A:D4
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-09-25T20:22:06+00:00

Server-presented chain · 3 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YE1
Issuer
C=US O=ISRG CN=Root YE
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
708
Serial (hex)
5DDD70DD31F801C85C186A7A04B80AFE
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

A2:37:2D:06:43:1E:97:16:36:5E:EE:D4:7E:C0:20:35:14:97:D1:82:FC:C0:38:E4:57:E5:81:68:A0:3C:AC:07
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
BB:20:CA:47:0B:FE:D7:E5:9C:F9:8F:09:2A:A3:8C:37:45:B1:BC:D8
authorityKeyIdentifier
A3:C8:26:5A:8E:A1:4C:D0:35:63:FC:9B:23:C8:3A:AE:56:F3:4F:56
authorityInfoAccess
CA Issuers - URI:http://ye.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://ye.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YE
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X2
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2169
Serial (hex)
872165FC34B6E5FBA8ADD5B3705FB53A
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

0F:C0:90:1C:CA:2B:AE:9E:9F:DB:B0:2D:50:D0:2F:10:94:F7:B3:66:72:08:69:91:B9:E8:97:62:6D:C4:85:F0
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
A3:C8:26:5A:8E:A1:4C:D0:35:63:FC:9B:23:C8:3A:AE:56:F3:4F:56
authorityKeyIdentifier
7C:42:96:AE:DE:4B:48:3B:FA:92:F8:9E:8C:CF:6D:8B:A9:72:37:95
authorityInfoAccess
CA Issuers - URI:http://x2.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x2.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 3

Subject
C=US O=Internet Security Research Group CN=ISRG Root X2
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
2169
Serial (hex)
6C8F1DC727C7117F7BAF853AC980F9CD
Signature
RSA-SHA256
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

EE:5F:7A:BD:69:81:BB:02:55:63:2C:D8:F4:92:83:45:1B:4B:18:84:4D:12:04:0B:44:EE:00:F0:7B:8F:E2:C6
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
7C:42:96:AE:DE:4B:48:3B:FA:92:F8:9E:8C:CF:6D:8B:A9:72:37:95
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-----
MIIEcDCCAligAwIBAgIQbI8dxyfHEX97r4U6yYD5zTANBgkqhkiG9w0BAQsFADBP
MQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJuZXQgU2VjdXJpdHkgUmVzZWFy
Y2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBYMTAeFw0yNjA1MTMwMDAwMDBa
Fw0zMjA5MDIyMzU5NTlaME8xCzAJBgNVBAYTAlVTMSkwJwYDVQQKEyBJbnRlcm5l
dCBTZWN1cml0eSBSZXNlYXJjaCBHcm91cDEVMBMGA1UEAxMMSVNSRyBSb290IFgy
MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEzZvVn4CDCuwJSvMWSj5cz3es3mcFDR0H
ttwW+1qLFNvicWDEukWVEYmO6gbf9yoWHKS5xcUy4APgHoIYOIvXRdgKam7mAHf7
AlF9ItgKbppbd9/w+kHsOdx1ymgHDB/qo4H1MIHyMA4GA1UdDwEB/wQEAwIBBjAd
BgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIwDwYDVR0TAQH/BAUwAwEB/zAd
BgNVHQ4EFgQUfEKWrt5LSDv6kviejM9ti6lyN5UwHwYDVR0jBBgwFoAUebRZ5nu2
5eQBc4AIiMgaWPbpm24wMgYIKwYBBQUHAQEEJjAkMCIGCCsGAQUFBzAChhZodHRw
Oi8veDEuaS5sZW5jci5vcmcvMBMGA1UdIAQMMAowCAYGZ4EMAQIBMCcGA1UdHwQg
MB4wHKAaoBiGFmh0dHA6Ly94MS5jLmxlbmNyLm9yZy8wDQYJKoZIhvcNAQELBQAD
ggIBAD2/e9frmMxNpCV03qUHegg+MV2wz9644YoXdqtH8RyWYcBO7xfjjGEXdU1e
/o0OkEFiynUCOSIk/vLLo7ttz6CPAeNlWfC0XNkoGeWgK6jjXvozBaGuGH5n0Ufo
shMeWTuURqNN5G00sSXDTBrpp2+mgvdZQjb8K11TYMA25QA+YHNfbIEL0BniAhKS
2gsnJjSzrdZLI+EZ7SEyqdR2rkjd1KutLDU+n3TFyxjniZVGur4YlhMP3mY/dV95
IruAkkjOZier6hGBdEgZXXvaCz9u9iVEadsIE75pAGL8oHV5vxdARDiotRpul1IN
/UZwzAbrfUFcw1HkAcYD/mlZfnQ2ieCF2MS7j3Vhv7JPDKp45fmykmzYNSrumRW0
upFFKDBOoF7hsOb7oLyHS+Uft6jOUfOrogj8YUx38hKb2K20r42OgsSdDdxdeYWc
MS3Sb6mwJeSZEYxJ2gaXnDSPaKhhrNkYwljyVQyr4Nq+MEJytXNTnHqaAcrNwZlV
pcJL1KBnMrMjP7eanvUwL3FYj3cF17jtboLt7gLoi4+2rWZFvn+w54jmd/FIuhhZ
cEaU/wvU6BUNMtcVquVGHp7itQeDth5j+XL3j4WJ2SABwzUl6OeYdgpIt/ITZa+p
TT0mQ/r5XyA4MEAiabn7XJjvCERlF2dcn2wqJw+CreTkkQ2R
-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

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