Your curiosity.
Your privacy.
No account. No advertising trackers. Here is what happens when you look up a domain.
Domain lookups
Your query is processed by our server and sent to public certificate or DNS services to retrieve results. Search data is public infrastructure information. Cached results may be shared between visitors for up to seven days to keep lookups fast and reduce repeated requests.
Fair use, without accounts
We use a protected, one-way identifier derived from your IP address to enforce request limits. IPv6 addresses in the same /64 network share a limit. Raw IP addresses are not stored by the application in rate-limit counters. These counters expire automatically, usually within one day.
Your browser
Recent searches are kept in this page’s memory while it is open. We save your appearance preference on this device. We do not use advertising cookies, analytics cookies, or browser storage to follow you across websites.
Hosting and infrastructure
Our hosting and infrastructure services may process IP addresses, request URLs, and technical logs to deliver and protect the service. Their retention policies also apply. Do not submit secrets or personal information as domain queries.
Using the API
The public API shares the same request limits as the website. Use the service responsibly, respect applicable rules, and only investigate infrastructure you are authorized to assess. Historical certificate records do not establish that a hostname currently exists or is reachable.