SSL
SSL certificate lookup
SSL Certificate Lookup
View SSL certificates issued for a domain via Certificate Transparency logs.
How to use the SSL tool
TLS/SSL certificates prove a domain is who it claims to be and encrypt traffic in transit. Every certificate issued is logged in public Certificate Transparency (CT) logs, which this tool searches via crt.sh. It lists the certificates ever issued for a domain, who issued them, when they expire, and whether they are still valid — invaluable for auditing your own domains or checking a third party.
- 1 Enter a domain name, for example dowithsudo.com.
- 2 Click Lookup to query crt.sh certificate transparency logs.
- 3 Review the list: common name, issuer, expiry date, and Subject Alternative Names (SANs).
Example: Lookup dowithsudo.com
dowithsudo.com
Common name: dowithsudo.com Issuer: (certificate authority) Expires: (date) SANs: dowithsudo.com, www.dowithsudo.com
SSL FAQ
What is Certificate Transparency?
It is a public, append-only log of all TLS certificates issued. Browsers and authorities rely on it to detect misissued certificates, and it lets anyone audit the history of certificates for a domain.
How do I check when my certificate expires?
Look up your domain here, or check directly in a browser by clicking the padlock in the address bar. Set up expiry monitoring so you renew before browsers start warning visitors.
What are Subject Alternative Names (SANs)?
SANs are the extra hostnames a single certificate covers, such as www.dowithsudo.com alongside dowithsudo.com. Modern certificates rely on SANs instead of the old common-name field.
Is it normal to see many certificates for one domain?
Yes. Every renewal and every issuance creates a new certificate entry in CT logs, so older ones naturally accumulate. Only the current, valid ones matter for visitors.
