GRASSMARLIN vs Nautilus OT: side-by-side comparison (2026)
GRASSMARLIN is a free OT asset discovery solution. Nautilus OT is a commercial OT asset discovery solution by Nautilus. Features, integrations, deployment and the company behind each one, side by side.
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Passively maps and visually displays ICS/SCADA network topology for network security
Side-by-side comparison
Feature
GRASSMARLIN
Nautilus OT
Pricing model
Free
Commercial
Category
OT Asset Discovery
OT Asset Discovery
Deployment and fit
Deployment type
On-Premises
On-Premises
Company size fit
Mid-Market, Enterprise
Mid-Market, Enterprise
Open source
GitHub stars
1,000
–
Last commit
Aug 2017
–
Company
Company
–
Nautilus
Use cases and capabilities
SCADA
Yes
No
Network Topology
Yes
No
Critical Infrastructure
No
Yes
Network Visibility
No
Yes
Network Monitoring
No
Yes
Anomaly Detection
No
Yes
Ransomware
No
Yes
Vulnerability
No
Yes
Security Compliance Training
No
Yes
Network Discovery
No
Yes
Core features
No features listed
6 features listed
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