About this tool
Because certificate issuance is publicly logged, this is a way to see a domain's certificate history and discover related subdomains named on the same certificates, without ever connecting to the live website.
Example inputs: example.comdigitpol.comlogin.example.net
What the result shows
- Issuer
- The certificate authority that issued the certificate.
- Names
- All domain and subdomain names listed on the certificate, which can reveal related hostnames.
- Logged at
- When the certificate was recorded in the public transparency log.
- Validity window
- The not-before and not-after dates defining when the certificate is valid.
- Serial number
- The certificate's unique identifier assigned by its issuer.
Investigation use cases
- Finding related subdomains such as login or pay portals named on the same certificate
- Establishing when a domain was first prepared for HTTPS as a timeline signal
- Comparing certificate issuers between a genuine site and a suspected clone
- Checking whether a suspicious site is using a newly issued certificate consistent with a recent campaign
Limitations
Results come from a public log and are capped at 100 certificates per query, the search does not make a live TLS connection to the site, and a certificate's existence does not confirm a certificate is still actively deployed or confirm who controls the server today.
Frequently asked questions
Does this connect to the website to check its live certificate?
No, this searches the public certificate transparency log only; no connection is made to the domain's server.
Can this show every certificate ever issued?
It returns up to 100 matching log entries; very high-volume domains may have more certificates than the result includes.
Why do unfamiliar subdomains appear in the results?
Certificates can name multiple hostnames, so related subdomains such as mail or admin portals can surface even if they were not searched for directly.
Is the lookup free?
Yes, within daily limits; a sealed report is a paid or account feature.
Need evidence you can keep?
Every lookup produces a full public-source report sealed with a SHA-256 digest. Accounts keep a saved history and can download the DIGITPOL PDF report.