Shodan

What it is

Shodan is a commercial search engine and internet-intelligence platform, operated by Shodan, that continuously indexes banners and metadata from devices and services reachable on the public internet and makes them searchable via the website, API, CLI clients and browser extensions.

What it helps with

- Search for exposed services, products and misconfigurations by banner, port or metadata.
- Research the internet-facing footprint of an organisation, IP range or technology.
- Enrich IP and host data for investigations and reconnaissance.
- Monitor owned ranges for new or unexpected exposure (Shodan Monitor on paid tiers).
- Integrate lookups and streaming data into other tools through the developer API.
- Support defensive attack-surface management as well as authorised external reconnaissance.

Who it's for

Security researchers, threat-intelligence and ASM teams, penetration testers doing external recon, and IT teams watching their own public exposure.

Worth knowing

A free account enables basic search and a limited API; Membership (one-time) and subscription plans unlock more filters, query credits, monitoring and commercial use (details on account.shodan.io/billing). Querying public internet data can still raise legal and policy issues depending on jurisdiction and target — use it in line with applicable law and organisational rules. Do not treat search results as permission to access systems. Attribution: product scope from shodan.io; plan structure from the official billing/compare page.