Search the public Certificate Transparency logs: 45B certificate records. List a domain's subdomains, lok up certs by hostname or fingerprint, keyword-searc recent issuance to catch impersonation. Web, CSV exort, API and an MCP connector. Free to start.
Hi Product Hunt! I built ctlogs.io because Certificate Transparency logs are one of the earliest public signals of new infrastructure, and searching them well is hard. ctlogs.io indexes 45B+ certificate records so you can list every subdomain of a domain, look up a certificate by hostname or fingerprint, and keyword-search recent issuance to catch phishing and brand impersonation as it appears. Guests get 3 searches a day, a free account 5 per query type, no card. Paid plans add the API, CSV export and an MCP connector so your AI assistant can query the index directly. It comes from the team behind abtdomain.com, where we work on domain data every day. Happy to answer questions about CT, the data or the API.