ctlogs.dev - Certificate Transparency Search
ctlogs.dev is a Certificate Transparency search engine and API for security teams. It indexes all public CT logs, so you can find every TLS certificate issued for your domains and subdomains, or search by organization name, serial number, SHA-256 fingerprint or public key. Teams use it to map an organization’s external attack surface, discover forgotten subdomains and shadow IT, investigate suspicious certificates, and audit which certificate authorities issue for them.
Every search on the site is also available through a JSON REST API with an OpenAPI spec and client libraries for JavaScript/TypeScript and Python. A free API key is available for non-commercial use; paid plans add higher volume, commercial use and full certificate history back to 2013, plus hostname history and first-seen dates.