Overview

Profundis is a search engine for internet infrastructure. Where Google crawls and ranks web pages, Profundis indexes the machines and records behind them: reachable hosts and their open ports, the TLS certificates they serve, and DNS records. If you've used Shodan or Censys, it's the same category of tool.

The index is built entirely from public sources (certificate transparency logs, public DNS data, internet archives, other search engines, IANA), then enriched: when a host is discovered, lightweight Profundis robots collect a few basic signals from it (web title, response headers, status code). Nothing intrusive: no authentication attempts, no injection, no deep probing. Billions of services are indexed, 15 to 25 million hosts get refreshed on a typical day (roughly twice that for DNS), and nothing is ever deleted, so old records stay searchable as infrastructure history.

How to use it?

You don't need an account to search. Run a sample hosts search or DNS search, or type your own domain into the search bar. The fastest way to refine results is to click a value inside any result card to add it to or exclude it from your query, so you can narrow things down before learning the query syntax.

What can I do with it?

Searches use wildcards (*) across dozens of fields, so you can go from a single domain to its whole exposed footprint (hosts, ports, certificates, DNS history) in a handful of queries. A security team can see which of its own assets are reachable from the internet; a researcher or bug bounty hunter can map a target's legitimate testing scope.

Beyond one-off searches, you can set up alerts to be notified the moment a new host matching your criteria is first ingested; you only hear about genuinely new assets, never ones already known. And everything searchable in the UI is reachable from the API with a token, so results can flow straight into your own tooling.