What Is Shodan? How It Works, Search Syntax & Alternatives
Everything you need to know about Shodan — the world's first search engine for internet-connected devices — and how modern alternatives like Zondex compare.
What Is Shodan?
Shodan is a search engine that indexes internet-connected devices rather than web pages. Created by John Matherly in 2009, it continuously scans the internet and catalogs information about every device it finds — from web servers and routers to webcams, ICS/SCADA systems, and IoT devices.
Often called "the search engine for hackers," it's more accurately an internet intelligence platform used by researchers, pentesters, and IT admins. It works by sending connection requests to IP addresses across the IPv4 space, then storing the response banners.
Shodan has indexed billions of devices. However, its pricing model and interface have remained relatively static, leading to modern alternatives with improved functionality.
How Does Shodan Work?
Port Scanning
Shodan generates random IPs and probes them on specific ports (80, 443, 22, 21, 3389…), randomizing to avoid detection and distribute load.
Banner Grabbing
When a port responds, it captures the banner — HTTP headers and titles, SSH version strings, and the full SSL/TLS certificate chain.
Enrichment
Raw data is enriched with GeoIP, ASN/org info, reverse DNS, and vulnerability mappings, identifying products and versions via fingerprinting.
Indexing & Search
Everything is stored and made searchable through the web interface, API, and CLI — filterable by country, port, product, org, OS, and more.
Shodan Limitations & Why Users Switch
Expensive Paid Plans
Membership costs $69/month, Small Business $359/month. The free tier is extremely limited.
Slower Query Performance
Complex queries can take several seconds. Zondex, built on ClickHouse, returns results in under a second.
Dated Interface
Shodan's UI hasn't changed much in years. Zondex offers a modern, dark-mode-first interface with AI search.
Limited Free API
Shodan's free API is rate-limited and lacks features. Zondex offers a REST API with Python/Go SDKs on all plans.
Zondex: The Modern Shodan Alternative
Zondex was built from the ground up as a next-generation internet search engine, addressing the limitations Shodan users have struggled with for years — a ClickHouse-powered backend, modern UI, and generous free tier.
Free Searches
Indexed Hosts
Query Response
Frequently Asked Questions
What is Shodan used for?
Is Shodan legal to use?
Is Shodan free?
What are the best Shodan alternatives?
Can Shodan see my computer?
How does Shodan compare to Zondex?
Try the Modern Alternative to Shodan
Zondex offers everything Shodan does — faster, cheaper, and with a better interface.