Assetnote ASM vs Subfinder: 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. Subfinder 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.
Reconnaissance teams conducting external attack surface mapping will get the most from Subfinder; its passive enumeration approach surfaces subdomains without triggering WAF alerts or leaving detectable scanning noise. With 12,248 GitHub stars and active community contributions, the tool consistently outpaces commercial alternatives on speed and accuracy across public DNS sources. Skip this if you need active probing, WHOIS integration, or post-enumeration validation; Subfinder stops at the list.
