Assetnote ASM vs massdns: Side-by-Side Comparison (2026)
Features, pricing, ratings, and pros & cons — compared head-to-head.
Assetnote ASM is a commercial external attack surface management tool by Assetnote. massdns is a free external attack surface management tool. Compare features, ratings, integrations, and community reviews side by side to find the best external attack surface management fit for your security stack.
CST VerdictBased on our analysis of NIST CSF 2.0 coverage, core features, company size fit, deployment model, here is our conclusion:
Mid-market and enterprise security teams managing sprawling external infrastructure will get the most from Assetnote ASM because its hourly asset discovery actually catches exposures before your business units spin up new services, not weeks after. The platform covers ID.AM and DE.CM across NIST CSF 2.0, meaning you're building a real asset inventory while monitoring it continuously, and the exploit-based verification eliminates the noise that buries actionable findings in traditional scanners. Skip this if your organization lacks the headcount to operationalize a workflow-driven program; Assetnote's strength is enabling lean teams to prioritize, not giving you a dashboard to ignore.
Penetration testers and security researchers running subdomain enumeration campaigns will get the most from massdns; its multi-threaded stub resolver processes 350,000+ queries per second, making it the fastest option for bulk DNS reconnaissance at scale. The 3,417 GitHub stars reflect actual adoption in red teams, and the free pricing means zero friction for integration into custom reconnaissance pipelines. Skip this if your team needs a managed, point-and-click subdomain discovery tool; massdns requires command-line comfort and assumes you're building automation around raw DNS data.
