OT Asset Discovery Tools 2026
OT asset discovery tools build and maintain an inventory of everything running on your operational technology and connected-device estate: PLCs, RTUs, HMIs, engineering workstations, building management systems, medical devices, and the long tail of IoT nobody documented when it was installed. The hard part is not counting devices. It is doing so on networks where active scanning can knock a controller offline, where protocols like Modbus, DNP3, and PROFINET are foreign to IT-grade tools, and where assets sit untouched for fifteen years. These tools lean heavily on passive traffic monitoring, with selective safe polling, to deliver visibility without disturbing the process. If you run a plant, a hospital, a utility, or a smart building, this is the foundation every other OT control depends on, because you cannot patch, segment, or monitor what you have never seen.
We cover 16 OT Asset Discovery tools, 5 free and 11 commercial.
Accuracy and depth improve over time. Last reviewed Sep 2026. Is something off? Reach out.
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New to this category? What is OT Asset Discovery?
Generates an OT asset inventory and vulnerability list as Excel/Power BI reports
Cloud-based IoT/OT asset intelligence engine for device profiling and OEM detection.
Agentless OT data acquisition platform for passive asset & traffic visibility.
Physical security device visibility, inventory, and vulnerability mgmt platform.
API for device identification & CVE enrichment using device fingerprinting.
Network device & service visibility platform for ISPs using device fingerprinting.
Database of 1M+ xIoT/OT/IoMT device profiles for CPS asset coverage.
Remote maritime IT/OT asset discovery & vuln assessment via software agent.
OT asset discovery and inventory platform for industrial environments
OT/IoT asset discovery and threat detection platform for industrial environments
Active polling add-on for OT/IoT asset discovery and configuration data
Ultimate Internet of Things/Industrial Control Systems reconnaissance tool powered by Shodan.
Passively maps and visually displays ICS/SCADA network topology for network security
A tool for scanning networks, enumerating Siemens PLCs, and gathering detailed information about them.
A Digital Bond research project to enumerate ICS applications and devices
How to choose OT Asset Discovery tools
- Confirm the discovery method matches your risk tolerance: passive monitoring via SPAN or TAP is the safe default for fragile process networks, and any active polling should be opt-in, protocol-aware, and rate-limited so it never disrupts a controller.
- Check protocol and vendor coverage against your actual environment, not a glossy list. Ask which industrial protocols are deep-parsed versus merely detected, and whether the tool fingerprints your specific PLC, drive, and RTU makes down to firmware version.
- Look at depth of asset attributes, not just an IP count. You want make, model, firmware, serial, slot-level backplane detail, and communication relationships, because that is what feeds vulnerability matching and segmentation later.
- Test how it handles the IT/IoT/OT overlap. Many estates mix building management, cameras, medical or printing devices, and IT endpoints on the same segments, so the tool should classify all of them, not only the Purdue Level 1 and 2 gear.
- Evaluate deployment fit for distributed and air-gapped sites: sensor footprint, support for remote or low-bandwidth locations, and whether it runs fully on-prem without phoning home from sensitive facilities.
- Look past inventory to what it connects to. Discovery only earns its keep if it exports clean data to your CMDB, vulnerability program, and SIEM, so check the integrations and API quality before you commit.
OT Asset Discovery Tools FAQ
Common questions about OT Asset Discovery tools, selection guides, pricing, and comparisons.
OT asset discovery is the process of identifying and inventorying every device on an operational technology network, including PLCs, RTUs, HMIs, engineering workstations, and connected IoT. Tools in this category typically use passive network monitoring to map assets, their firmware, and their communication paths without disrupting industrial processes, creating the baseline inventory that patching, segmentation, and threat detection all depend on.
IT discovery tools often rely on active scanning and agents that can crash or reboot industrial controllers, which is unacceptable in a live plant. They also do not speak protocols like Modbus, DNP3, or PROFINET, so they miss or misidentify OT gear. Purpose-built OT tools default to passive monitoring and deep industrial protocol parsing, giving you accurate device detail without touching the process.
Asset discovery is the visibility layer: the accurate, continuously updated inventory of what exists on the network. Many vendors bundle it inside larger OT security platforms that add vulnerability management, segmentation, and threat detection. Discovery is the foundation those features run on, so even when you buy a full platform, the quality of its asset inventory determines whether the rest of it works.
Open-source passive analyzers exist and can prove value on a single segment, but they leave you to handle protocol parsing, fingerprint databases, multi-site rollout, and integrations yourself. Commercial tools earn their cost through maintained device libraries, safe polling, and CMDB, SIEM, and vulnerability feeds. For more than one site or any regulated environment, the commercial route usually pays back quickly in coverage and support.
