SSL Certificate Checker - Free Tool

Interactive intelligence tool

Run the check, then ship the workflow

Use the browser tool for a fast answer, then move the same logic into scripts, monitoring, or product flows when it becomes repeatable.

1

Start with the live form

Enter a domain, URL, IP, email, or record and get a focused result without setup.

2

Review decision-ready signals

Outputs highlight statuses, risks, records, and next actions instead of raw provider noise.

3

Automate the winning workflow

Use the request and response examples to turn a one-off check into an API call or recipe.

What this tool helps you decide

Each page is shaped around a practical operational question, not just a raw lookup.

Signal

See the current DNS, registration, security, pricing, or reputation evidence.

Context

Compare the result with related checks so the next move is easier to trust.

Action

Copy examples, open linked tools, or move into API documentation when you need scale.

Trust signals before you integrate

Transparent docs, authenticated requests, and visible reliability details make it easier to evaluate DomScan before you ship.

Uptime API artifacts

OpenAPI, Swagger, Postman, CLI, SDK, and MCP links are one click away.

API keys Protected access

Authenticated endpoints use API keys with clear credit costs before you call them.

Free allowance Sign Up for Free

Start with 10,000 monthly credits and upgrade only when usage grows.

Active Example Request

Start from the curl and HTTP samples, then map the parameters into your application code.

Key Features

SSL Certificates

We query Certificate Transparency (CT) logs to show all SSL/TLS certificates issued for a domain. This includes the certificate issuer (Let's Encrypt, DigiCert, etc.), validity dates, Subject Alternative Names (SANs), and certificate chain. You can see both current and historical certificates.

Check SSL

Expired or misconfigured SSL certificates cause browser security warnings that damage user trust and hurt SEO rankings. Certificate monitoring helps you: renew before expiration, detect unauthorized certificate issuance, verify CAA records are working, and ensure proper SSL configuration across all subdomains.

Domain Watchlist

Yes! Use our domain watchlist feature to monitor certificate expiration. You can also use the REST API (GET /v1/certificates) to build custom monitoring. For comprehensive domain monitoring including SSL, DNS, and availability, check our domain health tool which provides an overall security score.

Example Request

Example Request http

GET /v1/certificates?domain=example.com

Example Response

Example Response json

{
  "certificates": [
    { "common_name": "example.com", "is_expired": false }
  ]
}

Built from the same API surface

The browser experience previews DomScan's structured endpoints, so teams can validate a use case before writing code.

Open API docs All Tools

Frequently Asked Questions

What information does the SSL certificate check show?

We query Certificate Transparency (CT) logs to show all SSL/TLS certificates issued for a domain. This includes the certificate issuer (Let's Encrypt, DigiCert, etc.), validity dates, Subject Alternative Names (SANs), and certificate chain. You can see both current and historical certificates.

Why is SSL/TLS certificate monitoring important?

Expired or misconfigured SSL certificates cause browser security warnings that damage user trust and hurt SEO rankings. Certificate monitoring helps you: renew before expiration, detect unauthorized certificate issuance, verify CAA records are working, and ensure proper SSL configuration across all subdomains.

What is Certificate Transparency and why does it matter?

Certificate Transparency (CT) is a public logging system where Certificate Authorities must record all issued SSL certificates. This helps detect misissued or fraudulent certificates. Our tool queries CT logs to show you every certificate ever issued for your domain - useful for security audits and detecting unauthorized subdomain certificates.

How can I find certificates for all my subdomains?

Our tool searches CT logs which include certificates for subdomains. This is also useful for subdomain discovery - if a certificate was issued for staging.example.com, it will appear in results even if you did not know that subdomain existed. Combine with our subdomain finder for comprehensive asset discovery.

Can I set up alerts for certificate expiration?