Certificate transparency search

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

Try:

Results for zh-cn.www.cloudflare.com

Checked 2026-11-15live lookup3494 ms

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

Logged certificates

20 certificates logged for zh-cn.www.cloudflare.com

The newest was issued 2026-11-09 by Google Trust Services and runs to 2027-02-07. Certificates here are renewed about every 5 days.

20 valid nowAs of 15 Nov 2026Cert Spotter

Newest valid

WE1

Certificates by issuer

Google Trust Services16 of 20
Let's Encrypt4 of 20

20 certificates from 2 issuers between 2026 and 2027. Filled bars are valid now, outlined bars have expired. The newest runs until 7 Feb 2027. Google Trust Services issued the most.

Logged

One log entry each

Valid now

The newest to 2027-02-07

Renewal cadence

5days

Median gap between issues

Issuer mix

12 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.

Certificates20

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

zh-cn.www.cloudflare.comWE1 · 2026-11-09 to 2027-02-07Valid
zh-cn.www.cloudflare.com
SHA-256
e7b87c6149ba9d69e9de7f17d507407aeecb7f804f08c8ea4d50ef5834c1b401
Issuer
Google Trust Services, WE1, US
Valid for
90 days, 84 days left
Log entries
1
Check the live certificate
zh-cn.www.cloudflare.comWR1 · 2026-11-09 to 2027-02-07Valid
zh-cn.www.cloudflare.com
SHA-256
63d6471600007533cf694458da0d4427d3c79b315a0937791e0ac992e5f1569d
Issuer
Google Trust Services, WR1, US
Valid for
90 days, 84 days left
Log entries
1
Check the live certificate
zh-cn.www.cloudflare.comWE1 · 2026-11-09 to 2027-02-07Valid
zh-cn.www.cloudflare.com
SHA-256
9ad9463fd7d4adc2d8cb6415d4b14320c44e96a5d73b2f7df04f7beb155b98ca
Issuer
Google Trust Services, WE1, US
Valid for
90 days, 84 days left
Log entries
1
Check the live certificate
zh-cn.www.cloudflare.comWR1 · 2026-11-09 to 2027-02-07Valid
zh-cn.www.cloudflare.com
SHA-256
95357200461bab4a7f404a2b12becb9d2c7bfe5e65f1199ff0ecfc15a554e243
Issuer
Google Trust Services, WR1, US
Valid for
90 days, 84 days left
Log entries
1
Check the live certificate
*.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
Check the live certificate
*.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
Check the live certificate
*.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, 74 days left
Log entries
1
Check the live certificate
*.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, 74 days left
Log entries
1
Check the live certificate
*.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
Check the live certificate
*.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
Check the live certificate
zh-cn.www.cloudflare.comWE1 · 2026-09-11 to 2026-12-10Valid
zh-cn.www.cloudflare.com
SHA-256
8796cb77ade8e630167fb88bd865af6331e3838f74151cc8957c606dbd576bb9
Issuer
Google Trust Services, WE1, US
Valid for
90 days, 24 days left
Log entries
1
Check the live certificate
zh-cn.www.cloudflare.comWR1 · 2026-09-11 to 2026-12-10Valid
zh-cn.www.cloudflare.com
SHA-256
5c03503963933983938f36b8ae613bd9c1dd49ecb8d4c5eaa24abfdeed5737ec
Issuer
Google Trust Services, WR1, US
Valid for
90 days, 24 days left
Log entries
1
Check the live certificate
zh-cn.www.cloudflare.comWE1 · 2026-09-11 to 2026-12-10Valid
zh-cn.www.cloudflare.com
SHA-256
5ee819ebba745832e0567b85924c2a7fc9493a9e2290e34b78bac429da981079
Issuer
Google Trust Services, WE1, US
Valid for
90 days, 24 days left
Log entries
1
Check the live certificate
zh-cn.www.cloudflare.comWR1 · 2026-09-11 to 2026-12-10Valid
zh-cn.www.cloudflare.com
SHA-256
ca126f2c78eb64402f0640bb62e8d0ebec1df343ac97b7d89c3e2c3815ce1f6f
Issuer
Google Trust Services, WR1, US
Valid for
90 days, 24 days left
Log entries
1
Check the live certificate
*.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, 15 days left
Log entries
1
Check the live certificate
*.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, 15 days left
Log entries
1
Check the live certificate
*.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
Check the live certificate
*.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
Check the live certificate
*.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, 5 days left
Log entries
1
Check the live certificate
*.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
Check the live certificate

Where this came from

1 of 2 sources answered

Cert SpotterDone0.5 s
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) · 11 KB

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  "domain": "zh-cn.www.cloudflare.com",
  "includeSubdomains": false,
  "excludeExpired": true,
  "sources": [
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      "id": "certspotter",
      "name": "Cert Spotter",
      "status": "ok",
      "ms": 491
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    {
      "id": "crtsh",
      "name": "crt.sh",
      "status": "failed"
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  "asOf": "2026-11-15T21:53:31.927Z",
  "stale": false,
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    "rawEntries": 20,
    "firstLogged": "2026-08-23",
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      "notBefore": "2026-08-23",
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      },
      "notBefore": "2026-08-23",
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      "names": [
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      ],
      "kind": "unknown",
      "revoked": false,
      "logEntries": 1,
      "lane": 1
    }
  ],
  "next": null
}

Next step

Subdomain finderWhich names appear in these certificates?
Check zh-cn.www.cloudflare.com in Subdomain finder
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Check zh-cn.www.cloudflare.com in SSL checker
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Open in Certificate decoder

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

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.
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.
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.
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 see	What it means
Renewal cadence	The 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 renewal	Often an ECC and an RSA certificate issued together, so older clients can still connect.
Wildcard	A name starting with `*.` covers every name one level below it. It is the reason a subdomain list can look short.
Email address in the names	Some certificates, such as S/MIME certificates, name a person. They are shown in the list and left out of subdomain results.
Revoked	Reported 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

Description for AI agents · OpenAPI · llms.txt

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Make and convert

Certificate transparency search

Results for zh-cn.www.cloudflare.com

20 certificates logged for zh-cn.www.cloudflare.com

Next step

What Certificate Transparency is

How to use it

Why it asks two sources

Reading the results

What it cannot tell you

Questions people ask

Use it from AI, the API or the command line

20 certificates logged for zh-cn.www.cloudflare.com

Next step

What Certificate Transparency is

How to use it

Why it asks two sources

Reading the results

What it cannot tell you

Questions people ask

Use it from AI, the API or the command line

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