crt.sh

Domain certificates and subdomains

Public certificate transparency search for issued certificates and names they cover.

Search certificates

Search certificates

Find issued certificates and the domain names they reveal on crt.sh. Expired certificates are excluded by default; results are limited to the newest matching certificates.

Your information

Domain

Domain to search, for example example.com.

Max ResultsOptional

Maximum number of certificates to return, for example 100.

Include ExpiredOptional

Include expired certificates, for example true.

1 credit per completed run

The same inputs also work from your code or an AI assistant. See For developers.

Example results

Certificates and domains

Certificates

Domain names

*.example.com
dev.example.com
example.com
m.example.com
products.example.com
support.example.com
www.example.com

About the crt.sh tool

crt.sh’s Search certificates method returns matching certificates and DNS names for a required domain.

Search certificates returns newest certificates first; optionally include expired certificates or set a maximum result count.

Built from crt.sh. Last checked Sep 29, 2026.

Actions

Search certificates

1 credit

Find issued certificates and the domain names they reveal on crt.sh. Expired certificates are excluded by default; results are limited to the newest matching certificates.

What you provide

Field	Type	Required	Description
Domain`domain`	Text	Required	Domain to search, for example example.com.Example: example.com
Max Results`max_results`	Number	Optional	Maximum number of certificates to return, for example 100.Example: 100
Include Expired`include_expired`	Yes or no	Optional	Include expired certificates, for example true.Example: Yes

What you get

Field	Type	Description
Subdomains`subdomains`	List	Unique matching DNS names, sorted A-Z, including wildcards and the root domain when present.
Certificates`certificates`	List	Matching unique certificates, newest first.
Link`certificates[].link`	Text	Certificate page on crt.sh.Example: https://crt.sh/?id=29557945233
Crt Sh ID`certificates[].crt_sh_id`	Number	Example: 29557945233
Valid From`certificates[].valid_from`	Date	Example: 2026-09-24
Valid Until`certificates[].valid_until`	Date	Example: 2026-12-21
Names Covered`certificates[].names_covered`	List	DNS names listed on the certificate.
Serial Number`certificates[].serial_number`	Text	Example: 2caeeaf0743459d7e5f82a75123c58f3
Issuer Organization`certificates[].issuer_organization`	Text	Organization that issued the certificate.Example: Sectigo Limited

Example result

For Domain: example.com, Max Results: 100, Include Expired: Yes

JSON

{
  "subdomains": [
    "*.example.com",
    "dev.example.com",
    "example.com"
  ],
  "certificates": [
    {
      "link": "https://crt.sh/?id=29557945233",
      "crt_sh_id": 29557945233,
      "valid_from": "2026-09-24",
      "valid_until": "2026-12-21",
      "names_covered": [
        "*.example.com",
        "example.com"
      ],
      "serial_number": "2caeeaf0743459d7e5f82a75123c58f3",
      "issuer_organization": "Sectigo Limited"
    },
    {
      "link": "https://crt.sh/?id=28361996564",
      "crt_sh_id": 28361996564,
      "valid_from": "2026-07-29",
      "valid_until": "2026-10-27",
      "names_covered": [
        "*.example.com",
        "example.com"
      ],
      "serial_number": "0624d0ab311558780b7d5213b9631831",
      "issuer_organization": "SSL Corporation"
    },
    {
      "link": "https://crt.sh/?id=28361996505",
      "crt_sh_id": 28361996505,
      "valid_from": "2026-07-29",
      "valid_until": "2026-10-27",
      "names_covered": [
        "*.example.com",
        "example.com"
      ],
      "serial_number": "62546d11b12882adbce18f65f9372286",
      "issuer_organization": "SSL Corporation"
    }
  ]
}

For developers

Call it from your code with one request. Change the values in input to run it on new data. To get an API key, open Developers at the bottom of Studio, turn on Developer mode and go to API keys.

cURL

curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 180 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@crt-sh",
  "visibility": "public",
  "operation": "search_certificates",
  "version": 1,
  "input": {
    "domain": "example.com",
    "max_results": 100,
    "include_expired": true
  },
  "response": {
    "format": "json"
  }
}'

What you can do with it

Review certificates issued for a domain
Identify subdomains revealed by certificates
Check certificate validity dates
Compare certificate issuer organizations
Review names covered by certificates

Questions about crt.sh

Can I run it with my own inputs?

Yes. Change the inputs in Studio and press Run, or send new inputs from your code, or ask a connected AI assistant.

Can I call this crt.sh tool as an API?

Yes. Send a POST request to /v1/query with your Fous API key and the inputs, and get JSON back.

How much does it cost?

Each completed run costs 1 credit. Failed runs without a completed receipt are free; completed work can remain charged if delivery is interrupted. With pay as you go, a credit costs 1¢. Monthly plans cost less per credit.

Do I need a crt.sh account?

No. You only need a Fous account.

How current is the data?

Fous gets the data from crt.sh when you run it. Some results are reused for up to 24 hours, and results that use your account or key are never reused. It was last verified on Sep 29, 2026.