The Censys alternative for researcher-friendly internet intelligence
Internet-wide host, certificate and DNS intelligence in one engine - with perceptual favicon search, an MCP server and a free researcher tier.
Profundis is a unified internet-intelligence search engine. Like Censys, it indexes internet-wide assets - hosts, services and TLS certificates - for attack-surface and security research.
Profundis brings these datasets together with live and historical DNS, WHOIS and virtual hosts under one field:value syntax, then adds perceptual favicon similarity and an official MCP server. It is operated from the EU and offers a researcher-friendly free tier with anonymous host/DNS previews.
Why Profundis
01A unified internet-intelligence engine - exposed hosts and services, DNS (live + historical/passive), WHOIS (with reverse/registrant lookups), TLS certificates and virtual hosts - all searchable in one place with a field:value syntax (wildcards, AND/OR/NOT).
02Favicon perceptual-similarity search (MMH3 + visual similarity) that finds visually similar favicons, not just exact icon-hash matches - Profundis’s signature differentiator.
03A free tier with an anonymous hosts and DNS preview, plus individual Solo and Professional plans. Teams and Business add shared organization workspaces and credits.
04An official MCP (Model Context Protocol) server, so AI agents like Claude can call Profundis search as native tools - AI-agent-native distribution.
05Operated by Perspective Analytics SAS, a software company based in France.
Profundis vs Censys
| Capability | Profundis | Censys |
|---|---|---|
| Internet-wide host & service data | ✓ Core feature | Core feature |
| TLS certificate search | ✓ Built in | Core feature |
| Unified DNS (live + historical/passive) | ✓ Built in | Supported |
| WHOIS + reverse/registrant lookups | ✓ Built in | Varies by plan |
| Field:value query syntax (wildcards, AND/OR/NOT) | ✓ Across all datasets | Supported |
| Favicon perceptual similarity | ✓ Visual similarity | Check current documentation |
| Official MCP server for AI agents | ✓ Native tools | Search tools (API access required) |
| Free tier with no-signup host/DNS preview | ✓ No signup to preview | Varies by plan |
| OSINT tools suite (typosquat, subdomains, registrant…) | ✓ Included | Varies by plan |
| Operator location | ✓ France (EU) | Check current documentation |
Capabilities and access conditions can change. Consult the linked publisher documentation where provided; an unverified feature is not an absent feature. Check the current plans before choosing Censys.
MCP sources checked on 5 October 2026. Censys and ZoomEye document search tools; the linked Netlas server provides documentation and reference information.
Frequently asked questions
Is Profundis a free Censys alternative?
Profundis has a free tier and an anonymous host/DNS preview that needs no signup, which makes it approachable for individual researchers. Higher quotas, the API and advanced tools are available on transparent credit-based paid plans.
How does Profundis compare to Censys for attack-surface management?
Both index internet-wide hosts and TLS certificates. Profundis unifies that with live and historical DNS, WHOIS with reverse/registrant lookups and virtual hosts in one query language, and adds perceptual favicon similarity to discover related and lookalike infrastructure.
Does Profundis offer certificate search?
Yes. TLS certificate data is one of the datasets Profundis unifies alongside hosts, DNS, WHOIS and virtual hosts, all searchable with the same field:value syntax.
Does Profundis have an API and an MCP server?
Yes. Profundis exposes an API and an official MCP server, letting AI agents like Claude run Profundis searches as native tools.
Who operates Profundis?
Profundis is operated by Perspective Analytics SAS in France. For data handling and retention, consult the privacy policy and organization documentation.
Compare with other tools
Comparison based on publicly available information. All trademarks are the property of their respective owners. Profundis is not affiliated with Censys.