BlockSieve

IP reputation and blocklist intelligence. Coming soon.

What we're building

A fast, developer-friendly API that checks IPv4 and IPv6 addresses against 7+ DNS-based blocklists and returns a category-weighted threat score.

Multi-DNSBL lookup

One request queries 7+ independent blocklists simultaneously

Weighted scoring

Malware and botnets weigh more than spam - scores reflect real threat level

IPv4 and IPv6

Full support for both address families

REST API

Single-IP checks, CIDR scanning, and self-serve key provisioning

Get early access

Join the waitlist for a free API key and product updates.