# zmap/zdns

Fast DNS Lookup Library and CLI Tool

Repository: https://github.com/zmap/zdns
Canonical: https://ross.abutalabs.com/products/zdns
Language: Go
License: Apache-2.0
License Family: permissive
Topics: dns, research, scanner
Last push: 2026-08-24T21:26:54+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 86, longevity 100
- inputs: {"age_days": 3714, "days_push": 9, "days_rel": 97, "gap_med": 9, "n_releases_24m": 8}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1131, forks 149 (observed 2026-08-28T04:03:42.506411+00:00)

## What it is
ZDNS is a high-speed DNS resolver library and CLI tool written in Go for performing large-scale DNS measurements and lookups. It includes its own recursive resolution code, a lookup cache, and modules for querying nearly every DNS record type with JSON output.

## Use cases
- perform large-scale DNS measurements for research
- bulk resolve A, AAAA, MX, NS, and TXT records for millions of domains
- run DNS lookups from the command line with JSON output like dig
- build custom DNS scanning tools using the resolver library
- query authoritative nameservers recursively at high speed
- measure DNS infrastructure for internet measurement studies

## When to choose
- you need to resolve or scan DNS records for very large domain lists quickly
- you want programmatic JSON DNS responses instead of dig's text output
- you are doing internet measurement research and need a fast, parallel DNS resolver
- you need a Go library embedding high-performance DNS resolution

## When to avoid
- you only need occasional interactive DNS lookups - dig or nslookup are simpler
- you need a general-purpose DNS server or recursive resolver for a network
- you want a GUI DNS tool or DNS monitoring dashboard

## Facets
- artifact type: cli-tool
- maturity: active
- function: search-engine, cli, developer-tools, networking
- domain: networking, security
- platform: windows, go, cli
- tags: dns, dns-lookup, dns-measurement, internet-scanning, resolver, zmap, research, command-line, linux, macos

## Member repositories
- zmap/zdns (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:42.506411+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:38:04.607536+00:00, confidence not recorded.
  - readme: https://github.com/zmap/zdns (fetched 2026-08-28T04:03:42.506411+00:00, sha c7eea04d90d5)
- Data as of 2026-08-30T08:39:29.467469+00:00.