Censys

Comprehensive internet-wide scanning platform providing visibility into hosts, networks, and certificates, enabling security teams to discover and analyze global attack surfaces.

OSINT Internet Scanning Certificate Analysis Attack Surface Management

Overview

Censys is a leading internet-wide scanning platform that provides comprehensive visibility into hosts, networks, and certificates across the global internet. Built by security researchers at the University of Michigan, Censys continuously scans the entire IPv4 address space and many IPv6 addresses, collecting detailed data about services, banners, and TLS/SSL certificates. Censys offers three primary datasets: IPv4 host data, IPv6 host data, and certificate data. The platform provides advanced search capabilities with a powerful query language, enabling security professionals to identify specific devices, discover misconfigured services, and analyze certificate transparency logs. Censys also offers a REST API for programmatic access and integrations with security tools. Key capabilities include vulnerability discovery, attack surface management, certificate analysis, and historical trend analysis. Censys is used by security teams, researchers, and government organizations for threat hunting, incident response, and understanding global internet security posture.

Primary Use Cases

✔ Identifying exposed devices and services across the global internet to assess security posture and discover vulnerabilities.

✔ Analyzing TLS/SSL certificates and certificate transparency logs to detect suspicious certificates and identify domain ownership.

✔ Monitoring global internet trends and security posture to understand emerging threats and infrastructure changes.

Frequently Asked Questions

Censys is an internet-wide scanning platform that provides visibility into hosts, networks, and certificates. While both Censys and Shodan scan the internet, Censys offers more detailed certificate analysis, more comprehensive historical data, and a powerful query language designed for security researchers and enterprise security teams.

Censys offers a free tier with limited search capabilities and result quotas. For advanced features, increased result limits, API access, and commercial use, Censys offers paid subscriptions including Academic, Pro, and Enterprise tiers.

Censys provides three primary datasets: IPv4 host data (services, banners, protocols), IPv6 host data (for many addresses), and certificate data (TLS/SSL certificates from public scans and certificate transparency logs).

Organizations use Censys to discover their public-facing assets, monitor for misconfigured services, track SSL certificate expirations and anomalies, detect potential vulnerabilities, and understand their overall attack surface to proactively address security risks.

Yes, Censys provides a comprehensive REST API that allows programmatic access to all search functionality, data retrieval, and analysis features. The API supports both free and paid tiers and integrates with various security orchestration and automation tools.

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Category Info

Open Source Intelligence (OSINT) tools for gathering and analyzing publicly available information from various sources including websites, social media, DNS records, public databases, and other open data sources for security investigations and threat intelligence.

Added On

August 18, 2026

Last Updated

August 18, 2026