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Certificate transparency search

See every publicly logged certificate for a domain, who issued each one, when, and which names it covers.

A domain name. We list certificates logged for it. Add a subdomain to narrow it.

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Matches the issuer name.

A date, YYYY-MM-DD.

25, 100 or up to 500 certificates.

Results for https://www.cloudflare.com/

Checked live lookup1354 ms

JSON
  • Cert Spotter answered. crt.sh didn’t, so wildcard and subdomain results may be missing.

Logged certificates

32 certificates logged for www.cloudflare.com

The newest was issued 2026-11-14 by Google Trust Services and runs to 2027-02-12. Certificates here are renewed about every 2 days.

32 valid nowAs of 15 Nov 2026Cert Spotter
Newest valid

WE1

Certificates by issuer
32 certificates from 2 issuers between 2026 and 2027. Filled bars are valid now, outlined bars have expired. The newest runs until 12 Feb 2027. Google Trust Services issued the most.
  • Google Trust Services18 of 32
  • Let's Encrypt14 of 32

32 certificates from 2 issuers between 2026 and 2027. Filled bars are valid now, outlined bars have expired. The newest runs until 12 Feb 2027. Google Trust Services issued the most.

Logged
32

One log entry each

Valid now
32

The newest to 2027-02-12

Renewal cadence
2days

Median gap between issues

Issuer mix
Google Trust Services 18, Let's Encrypt 14

16 certificates are wildcards. A wildcard covers every name one level below it, so it does not list them. The subdomain finder lists the names that appear in certificates.

Certificates32

Newest first. Without JavaScript every certificate on this page is listed.

  • timeline.www.cloudflare.com +1 nameWE1 · 2026-11-14 to 2027-02-12Valid

    timeline.www.cloudflare.com www.cloudflare.com

    SHA-256
    a9c83a8a7f8189a0c1965a599bcb544fabc0e890db641322fcf1e9bea5c794a4
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 88 days left
    Log entries
    1
  • timeline.www.cloudflare.com +1 nameWR1 · 2026-11-14 to 2027-02-12Valid

    timeline.www.cloudflare.com www.cloudflare.com

    SHA-256
    18a9e9042195446f9433e9c174ab30233a61f1a2df642130dacc9792ae33476c
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 88 days left
    Log entries
    1
  • timeline.www.cloudflare.com +1 nameWE1 · 2026-11-14 to 2027-02-12Valid

    timeline.www.cloudflare.com www.cloudflare.com

    SHA-256
    9119d025e1a89434c6c8f44f772bd558103f12165cc48e21d5eb5314b16e4752
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 88 days left
    Log entries
    1
  • timeline.www.cloudflare.com +1 nameWR1 · 2026-11-14 to 2027-02-12Valid

    timeline.www.cloudflare.com www.cloudflare.com

    SHA-256
    fc9ab6cd136f19416cfd2daf4938882ea2cda6c222518edbf880d4e420b6705a
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 88 days left
    Log entries
    1
  • www.cloudflare.com +1 nameYE2 · 2026-11-02 to 2027-01-31WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    452c946c9460c2ee75ca8cd236da7bf22ea833a8137ce50583bc5f2920ac2ed6
    Issuer
    Let's Encrypt, YE2, US
    Valid for
    89 days, 76 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYE1 · 2026-11-01 to 2027-01-30Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    84ff4d71ee8f55beebe1b753d06d41e627ff297509978b7ab3305571f61aa63b
    Issuer
    Let's Encrypt, YE1, US
    Valid for
    89 days, 75 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYR2 · 2026-11-01 to 2027-01-30Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    045d0758ed7db6e7a3a1ffaffb2cd8ca2a8185318d40422145af3259b106f72f
    Issuer
    Let's Encrypt, YR2, US
    Valid for
    89 days, 75 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYE2 · 2026-11-01 to 2027-01-30Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    1ead4a78920632799207e1fbefe1390d4c4841e97311e505a5cfb5d81fa5780c
    Issuer
    Let's Encrypt, YE2, US
    Valid for
    89 days, 75 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYR1 · 2026-11-01 to 2027-01-30Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    76b6e64db50377b6c02ae6c37ea5c0255b0df872bc6539941661a3208f4209d6
    Issuer
    Let's Encrypt, YR1, US
    Valid for
    89 days, 75 days left
    Log entries
    1
  • www.cloudflare.com +1 nameYR1 · 2026-11-01 to 2027-01-30WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    a2130b10acd9b5f18ae4e7c95a708eae68fc8b971cda0dd3f13e464a7fb3a583
    Issuer
    Let's Encrypt, YR1, US
    Valid for
    89 days, 75 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWE1 · 2026-10-31 to 2027-01-29WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    cd5c022f217e7287347f33f3d2490ec0b0661b3402e336ec403e7318a7e61d42
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 75 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWR1 · 2026-10-31 to 2027-01-29WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    159eaa461d0d777526b22c5b156c8fa5850f2a0a00c2fcc2ee1f8165e367890d
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 75 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWE1 · 2026-10-26 to 2027-01-24WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    4470700223c578cd1fe70e12d1d044bd596d59b8f629b2d3d61eff5e16d4e684
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 69 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWR1 · 2026-10-26 to 2027-01-24WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    f9e7543e37895eb6e5c00f3346b0733daa75ae2e44846ce4d6dd39a39bccf4df
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 69 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameWE1 · 2026-10-12 to 2027-01-10Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    7c794df05f61fe7b7ea841ef0803b847eb865ce24e3654a8da6c3cdc9e738d3d
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 56 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameWR1 · 2026-10-12 to 2027-01-10Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    d801e58955339c33103840b1ce2b4020a0d2c33b77a3c504f3383d01f7b4d472
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 56 days left
    Log entries
    1
  • *.cloudflare.com +1 nameYE2 · 2026-10-11 to 2027-01-09WildcardValid

    *.cloudflare.com cloudflare.com

    SHA-256
    af9a6def3035ed8636f620a607f7759c32f8a19893c80192b7e541ec4b006c4a
    Issuer
    Let's Encrypt, YE2, US
    Valid for
    89 days, 55 days left
    Log entries
    1
  • *.cloudflare.com +1 nameYR1 · 2026-10-11 to 2027-01-09WildcardValid

    *.cloudflare.com cloudflare.com

    SHA-256
    ec9871a574f41eda47bc055642bb8a795e9026dcd534e8dcfeadb3719b81f3b6
    Issuer
    Let's Encrypt, YR1, US
    Valid for
    89 days, 55 days left
    Log entries
    1
  • *.cloudflare.com +1 nameWE1 · 2026-09-18 to 2026-12-17WildcardValid

    *.cloudflare.com cloudflare.com

    SHA-256
    03f5ce83aa96f0e6104b45d5beb758fea22e512ef2125719afcedb633788f1af
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 31 days left
    Log entries
    1
  • *.cloudflare.com +1 nameWR1 · 2026-09-18 to 2026-12-17WildcardValid

    *.cloudflare.com cloudflare.com

    SHA-256
    02e241943fadd94345e018cb2c7ae9168ac4c044e389d369810ae38186bf62ca
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 31 days left
    Log entries
    1
  • timeline.www.cloudflare.com +1 nameWE1 · 2026-09-16 to 2026-12-15Valid

    timeline.www.cloudflare.com www.cloudflare.com

    SHA-256
    802c43b9f4a84d4107a1f06ddd3bd73c69897f675ca261490926f1ef643ee450
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 29 days left
    Log entries
    1
  • timeline.www.cloudflare.com +1 nameWR1 · 2026-09-16 to 2026-12-15Valid

    timeline.www.cloudflare.com www.cloudflare.com

    SHA-256
    3006d40720c3031350adf47037be249c9fbd986acda4c59d8d586b42075f459c
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 29 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYE2 · 2026-09-03 to 2026-12-02Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    cf80aa757e806acf837612acf5d13e499a210c04d6c029f084bad3660253b252
    Issuer
    Let's Encrypt, YE2, US
    Valid for
    89 days, 16 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYR1 · 2026-09-03 to 2026-12-02Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    2c612f9bf13a1b67c31740e523f0dc7b4a4e3ce26e957aadf029c1a65f2baae1
    Issuer
    Let's Encrypt, YR1, US
    Valid for
    89 days, 16 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYE2 · 2026-09-03 to 2026-12-02Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    3ec314edd2d01250acec05b2146b25e93cd24f003c52eda756d8c94e1968d755
    Issuer
    Let's Encrypt, YE2, US
    Valid for
    89 days, 16 days left
    Log entries
    1
  • blog.api.www.cloudflare.com +1 nameYR2 · 2026-09-03 to 2026-12-02Valid

    blog.api.www.cloudflare.com www.cloudflare.com

    SHA-256
    78e4d1d29ccf1314ae6112a8e5d2c7ca267a6f2798a8cd0cbe8a57dd643c1c76
    Issuer
    Let's Encrypt, YR2, US
    Valid for
    89 days, 16 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWE1 · 2026-09-02 to 2026-12-01WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    443388805fea16699c42513d99576283ab407a66ce9d0b217a0d4284cd6fabae
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 16 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWR1 · 2026-09-02 to 2026-12-01WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    1267325dc4ba138af33475eba185ba092a57a73f2323a3dcfb13e063066ebf7a
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 16 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWE1 · 2026-08-28 to 2026-11-26WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    7eb4bd98f443c9386800bbfccb8e7d571e97ca24770081e2f1df16ba3ef1c5a5
    Issuer
    Google Trust Services, WE1, US
    Valid for
    90 days, 10 days left
    Log entries
    1
  • www.cloudflare.com +1 nameWR1 · 2026-08-28 to 2026-11-26WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    a3c8c2d885e2c3bef2f66c79d563dc086fdf044e1c9bc8703076496dcc627fb3
    Issuer
    Google Trust Services, WR1, US
    Valid for
    90 days, 10 days left
    Log entries
    1
  • www.cloudflare.com +1 nameYE2 · 2026-08-23 to 2026-11-21WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    d57da07163158fc13fba7b1e819b9bca20cc7452c0122ed19db2de1c03784b5d
    Issuer
    Let's Encrypt, YE2, US
    Valid for
    89 days, 6 days left
    Log entries
    1
  • www.cloudflare.com +1 nameYR1 · 2026-08-23 to 2026-11-21WildcardValid

    *.www.cloudflare.com www.cloudflare.com

    SHA-256
    d747bd1b36bfac1d89fe40660453099d73dca59fb269c3a2326d614677cf1116
    Issuer
    Let's Encrypt, YR1, US
    Valid for
    89 days, 5 days left
    Log entries
    1
Where this came from

1 of 2 sources answered

  1. Cert SpotterDone1.4 s
  2. crt.shCouldn't readDidn't answer

crt.sh is free but often down. Cert Spotter is fast. We ask both and merge what they return. Credit: crt.sh by Sectigo and Cert Spotter by SSLMate. Revocation is only known for certificates Cert Spotter returned.

As of 15 Nov 2026. Results are kept for an hour so repeat searches are quick.

See the subdomains in these certificates: Subdomain finder.

Structured result (JSON) · 18 KB
{
  "domain": "www.cloudflare.com",
  "includeSubdomains": false,
  "excludeExpired": true,
  "sources": [
    {
      "id": "certspotter",
      "name": "Cert Spotter",
      "status": "ok",
      "ms": 1351
    },
    {
      "id": "crtsh",
      "name": "crt.sh",
      "status": "failed"
    }
  ],
  "asOf": "2026-11-15T18:42:16.727Z",
  "stale": false,
  "summary": {
    "certificates": 32,
    "rawEntries": 32,
    "firstLogged": "2026-08-23",
    "lastLogged": "2026-11-14",
    "currentlyValid": 32,
    "wildcards": 16,
    "issuers": [
      {
        "name": "Google Trust Services",
        "short": "Google Trust Services",
        "count": 18
      },
      {
        "name": "Let's Encrypt",
        "short": "Let's Encrypt",
        "count": 14
      }
    ],
    "cadenceDays": 2,
    "truncated": false,
    "newestEnd": "2027-02-12"
  },
  "certificates": [
    {
      "sha256": "a9c83a8a7f8189a0c1965a599bcb544fabc0e890db641322fcf1e9bea5c794a4",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Google Trust Services",
        "cn": "WE1"
      },
      "notBefore": "2026-11-14",
      "notAfter": "2027-02-12",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 88,
      "names": [
        "timeline.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
      "sha256": "18a9e9042195446f9433e9c174ab30233a61f1a2df642130dacc9792ae33476c",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Google Trust Services",
        "cn": "WR1"
      },
      "notBefore": "2026-11-14",
      "notAfter": "2027-02-12",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 88,
      "names": [
        "timeline.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
      "sha256": "9119d025e1a89434c6c8f44f772bd558103f12165cc48e21d5eb5314b16e4752",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Google Trust Services",
        "cn": "WE1"
      },
      "notBefore": "2026-11-14",
      "notAfter": "2027-02-12",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 88,
      "names": [
        "timeline.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
      "sha256": "fc9ab6cd136f19416cfd2daf4938882ea2cda6c222518edbf880d4e420b6705a",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Google Trust Services",
        "cn": "WR1"
      },
      "notBefore": "2026-11-14",
      "notAfter": "2027-02-12",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 88,
      "names": [
        "timeline.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
      "sha256": "452c946c9460c2ee75ca8cd236da7bf22ea833a8137ce50583bc5f2920ac2ed6",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Let's Encrypt",
        "cn": "YE2"
      },
      "notBefore": "2026-11-02",
      "notAfter": "2027-01-31",
      "validDays": 89,
      "state": "valid",
      "daysLeft": 76,
      "names": [
        "*.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    },
    {
      "sha256": "84ff4d71ee8f55beebe1b753d06d41e627ff297509978b7ab3305571f61aa63b",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Let's Encrypt",
        "cn": "YE1"
      },
      "notBefore": "2026-11-01",
      "notAfter": "2027-01-30",
      "validDays": 89,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "blog.api.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    },
    {
      "sha256": "045d0758ed7db6e7a3a1ffaffb2cd8ca2a8185318d40422145af3259b106f72f",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Let's Encrypt",
        "cn": "YR2"
      },
      "notBefore": "2026-11-01",
      "notAfter": "2027-01-30",
      "validDays": 89,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "blog.api.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    },
    {
      "sha256": "1ead4a78920632799207e1fbefe1390d4c4841e97311e505a5cfb5d81fa5780c",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Let's Encrypt",
        "cn": "YE2"
      },
      "notBefore": "2026-11-01",
      "notAfter": "2027-01-30",
      "validDays": 89,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "blog.api.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    },
    {
      "sha256": "76b6e64db50377b6c02ae6c37ea5c0255b0df872bc6539941661a3208f4209d6",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Let's Encrypt",
        "cn": "YR1"
      },
      "notBefore": "2026-11-01",
      "notAfter": "2027-01-30",
      "validDays": 89,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "blog.api.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    },
    {
      "sha256": "a2130b10acd9b5f18ae4e7c95a708eae68fc8b971cda0dd3f13e464a7fb3a583",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Let's Encrypt",
        "cn": "YR1"
      },
      "notBefore": "2026-11-01",
      "notAfter": "2027-01-30",
      "validDays": 89,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "*.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    },
    {
      "sha256": "cd5c022f217e7287347f33f3d2490ec0b0661b3402e336ec403e7318a7e61d42",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Google Trust Services",
        "cn": "WE1"
      },
      "notBefore": "2026-10-31",
      "notAfter": "2027-01-29",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "*.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
      "sha256": "159eaa461d0d777526b22c5b156c8fa5850f2a0a00c2fcc2ee1f8165e367890d",
      "serial": "",
      "issuer": {
        "country": "US",
        "org": "Google Trust Services",
        "cn": "WR1"
      },
      "notBefore": "2026-10-31",
      "notAfter": "2027-01-29",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 75,
      "names": [
        "*.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
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      "names": [
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        "cloudflare.com"
      ],
      "kind": "unknown",
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    },
    {
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      "validDays": 90,
      "state": "valid",
      "daysLeft": 31,
      "names": [
        "*.cloudflare.com",
        "cloudflare.com"
      ],
      "kind": "unknown",
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    },
    {
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      "notBefore": "2026-09-16",
      "notAfter": "2026-12-15",
      "validDays": 90,
      "state": "valid",
      "daysLeft": 29,
      "names": [
        "timeline.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 0
    },
    {
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      "state": "valid",
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      "names": [
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    },
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      },
      "notBefore": "2026-09-03",
      "notAfter": "2026-12-02",
      "validDays": 89,
      "state": "valid",
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      "names": [
        "blog.api.www.cloudflare.com",
        "www.cloudflare.com"
      ],
      "kind": "unknown",
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    },
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      },
      "notBefore": "2026-09-03",
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      "names": [
        "blog.api.www.cloudflare.com",
        "www.cloudflare.com"
      ],
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    },
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      ],
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  ],
  "next": null
}

Next step

What Certificate Transparency is

Certificate Transparency, or CT, is a set of public, append-only logs. When a certificate authority that browsers trust issues a certificate, it records it in several of these logs, and browsers such as Chrome and Safari refuse certificates that were not logged. The point is simple: if a certificate is issued for your domain, you can find out, even if you did not ask for it.

That makes CT the best public record of who has issued certificates for a name. It is how people notice a mistaken issuance, a forgotten test site that got a certificate, or a certificate authority that has been switched without telling the team.

This page searches those logs for you. Enter a domain and you get the certificates, a timeline grouped by issuer, and the numbers that matter: how many there are, how many are valid today, and how often they are renewed.

How to use it

  1. Enter a domainType a name such as example.org. A bare name lists certificates that name it. Add a subdomain, such as www.example.org, to narrow the search to that name.
  2. Decide about subdomainsSwitch on "Include subdomains" to list certificates for every name under the domain. It is the heavier question, so it can wait in a short queue, and the answer is kept for an hour so the next person gets it at once.
  3. Read the timelineEach lane is one issuer and each bar is one certificate, from the day it started to the day it ends. Filled bars are valid now, outlined bars have expired. A change of lane shows a change of authority, and a gap shows a lapse.
  4. Open a certificateEach row shows the names, the issuer, the dates, the serial number and the SHA-256 fingerprint when we have it, with a link to the entry on crt.sh.
Shell
# The same search from a terminal, as JSON
curl "https://lookupowl.com/api/v1/tools/ct-search?domain=example.org&includeSubdomains=true"

Why it asks two sources

crt.sh, run by Sectigo, is the standard way to search CT. It is free and thorough, and it is also slow and often unavailable. Cert Spotter, run by SSLMate, is fast and reports revocation, but it allows only a small number of questions.

So we ask both at once for a single name and merge what comes back. A precertificate and its final certificate, which crt.sh lists as two entries, become one row, and the "log entries" line says how many were merged. If one source does not answer, you get the other, with a note saying so. If both are down and we have a copy from an earlier search, you get that copy with its age on the page.

  • Both answered. The fullest result, with fingerprints and revocation where Cert Spotter returned the certificate.
  • One answered. The result is still useful, but wildcard and subdomain results can be missing when crt.sh is the one that failed.
  • A stored copy. Shown only when both are down, with how old it is.
  • Neither, and no copy. We say so plainly. The logs are on their side, not yours.

Reading the results

What you seeWhat it means
Renewal cadenceThe typical number of days between issues, from the median gap of recent certificates. Short cadences such as 60 or 90 days point to automated renewal.
Two certificates at each renewalOften an ECC and an RSA certificate issued together, so older clients can still connect.
WildcardA name starting with *. covers every name one level below it. It is the reason a subdomain list can look short.
Email address in the namesSome certificates, such as S/MIME certificates, name a person. They are shown in the list and left out of subdomain results.
RevokedReported by Cert Spotter. crt.sh does not report revocation, so a certificate only seen on crt.sh shows as not revoked.

Big domains have more certificates than one answer can hold. We then show the newest 100 (or the number you pick, up to 500) and say how many exist, and you can narrow the search by issuer or by date under More options.

What it cannot tell you

  • Logged is not the same as in use. CT shows that a certificate exists. It cannot show which one a server is serving. For that, use the SSL checker.
  • Private certificates are missing. Certificates from a private authority, such as a company's internal one, are not logged.
  • New certificates take a little while. A certificate can take a few minutes to show up after it is issued.
  • Very big domains are cut. An answer from the logs has a size limit, so for a domain with thousands of certificates we say the list is cut and suggest a filter.

To see the names themselves, try the subdomain finder, which reads the same certificates and lists the hosts, with where each one points now.

Questions people ask

What is crt.sh and why is this an alternative?

crt.sh is a free search over Certificate Transparency logs run by Sectigo. It is the standard tool, but it is often slow or down. This page asks crt.sh and Cert Spotter together and merges the answers, so you still get a result when one of them is not answering.

Does every certificate show up here?

No. Only certificates that were logged do, and browser-trusted authorities log nearly all of them. Certificates from private authorities are not logged, and a very new certificate can take a few minutes to appear.

Why does a certificate show 3 log entries?

A certificate is usually logged twice: first as a precertificate before issuance, then as the final certificate, and often in more than one log. We merge them into one row so a renewal is one line, and the entry count says how many were merged.

Can I search for a whole organisation?

Not here. The search is by domain name, with an option to include the names under it. Searching by organisation name needs a different kind of query that the free sources do not allow.

Why is "Include subdomains" slower?

It asks the logs for every certificate that names anything under the domain, which is far more work than one name. It uses crt.sh only, so it can wait in a short queue. The answer is kept for an hour, so a second search for the same domain is quick.

How do I find out which certificate a site is using now?

Use the SSL checker. It connects to the server and shows the certificate it really sends, with its chain and expiry. Certificate Transparency can only show what was issued.

Is the data private?

The logs are public by design, so the certificates are public. We keep a short-lived copy of each answer so repeated searches are quick, and we pace searches for the same domain to be kind to the logs.

Use it from AI, the API or the command line

Every LookupOwl tool is also a free API and an MCP tool, with no key and no account. This one is ct_search. Please be kind to the rate limits.

curl
curl "https://lookupowl.com/api/v1/tools/ct-search?q=example.org&excludeExpired=false&includeSubdomains=true"
MCP
claude mcp add --transport http lookupowl https://lookupowl.com/mcp