Resensor vs runZero
runZero is cyber asset attack surface management: it discovers and fingerprints assets across your internal network, OT and IoT, and cloud to build a complete inventory. Resensor is external attack surface management: the outside-in attacker view, validated and ranked by real-world exploitability with CISA KEV and FIRST EPSS. They answer different questions, and they work well together. Here is an honest comparison, including where each one leads.
Different jobs, not direct rivals. runZero is the asset inventory engine: deep, unauthenticated active and passive discovery that fingerprints everything on your network, including unmanaged IT, OT and IoT, and answers what do we have. Resensor is the external attacker view: it discovers your internet-facing surface, then validates and ranks what an attacker is most likely to exploit with CISA KEV and FIRST EPSS, and answers what can an attacker reach and what should we fix first. Many teams run runZero inside for inventory and Resensor outside for exposure validation.
How they compare
| Dimension | runZero | Resensor |
|---|---|---|
| Center of gravity | Cyber asset attack surface management (CAASM) and network asset inventory | External attack surface management plus evidence-based exposure validation |
| Vantage point | Inside the network and cloud via scanners, plus external | Outside-in only, agentless, nothing to deploy |
| Asset discovery depth | Deep active and passive fingerprinting across IT, OT and IoT | External assets: subdomains, hosts, certificates, services, cloud footprint |
| Unknown and unmanaged devices | A core strength, including OT and IoT | External unknowns: forgotten subdomains, shadow cloud, look-alike domains |
| Exploit prioritization | Integrates vulnerability data; inventory-first | CISA KEV and FIRST EPSS on every finding, ranked by real-world exploitability |
| Exposed cloud data | Inventories cloud assets | Open S3, GCS and Azure buckets; anonymous Redis, Mongo and Elasticsearch; secrets in client JavaScript |
| AI surface discovery | May appear in the inventory | Exposed model servers, vector databases, MCP, and notebooks, ranked |
| Brand and typosquat | Not a focus | Look-alike domain detection plus takedown packets |
| Validation evidence | Asset facts and fingerprints | Reachability re-check, screenshots, and non-destructive proof |
| Deployment | Lightweight scanners (Explorers) in your environment | None; outside-in SaaS |
| Best fit | Full asset inventory and internal CAASM, including OT and IoT | The external attacker view, validated and prioritized |
Comparison reflects each product's publicly described focus as of June 2026. Check each vendor's site for current capabilities.
Where each one leads
Where runZero leads
- Unauthenticated active and passive discovery that fingerprints almost anything
- Unmatched visibility into unmanaged IT, OT and IoT inside the network
- A rich, queryable asset inventory for full internal CAASM
- The stronger pick when you need to know every asset you actually have
Where Resensor leads
- The outside-in attacker view of your internet-facing surface, with nothing to deploy
- Exploit-aware prioritization with CISA KEV and FIRST EPSS on every finding
- Validation evidence, plus cloud data, AI, email spoofability and brand abuse in one place
- Third-party vendor ratings and MSP rollup, ranked by what an attacker would exploit
What Resensor does not do
To be precise: Resensor is external-only and agentless. It does not deploy a scanner inside your network, so it does not build an internal asset inventory or fingerprint OT and IoT devices on your LAN. That deep internal and operational-technology discovery is exactly where runZero leads. Resensor's job is what is reachable from the public internet, validated and ranked by real-world exploitability. The two are complementary, and many teams run both: runZero for the inventory, Resensor for the external exposure view.
The attacker's full external view, prioritized
If you already know your asset inventory and now need to answer what can an attacker reach, and what should we fix first, that is Resensor: continuous external discovery, then evidence-based validation with CISA KEV and FIRST EPSS, plus coverage of cloud data exposure, exposed AI services, email spoofability across SPF, DKIM and DMARC, and typosquatted look-alike domains. Pair it with a CAASM tool for complete internal inventory. See our full pricing, learn how validation extends attack surface management, or compare EASM with vulnerability scanning. You can also see how Resensor compares with Rapid7 and Intruder.
See what an attacker could actually exploit
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Start freeCommon questions
Is Resensor a replacement for runZero?
No, they do different jobs and work well together. runZero is cyber asset attack surface management: it discovers and fingerprints assets across your internal network, OT and IoT, and cloud to build a complete inventory. Resensor is external attack surface management: it takes the outside-in attacker view, then validates and ranks internet-facing exposures by real-world exploitability. Many teams run runZero for internal asset inventory and Resensor for external exposure validation.
Does Resensor discover internal, OT or IoT assets like runZero?
No. Resensor is external-only and agentless. It does not deploy a scanner inside your network, so it does not build an internal asset inventory or fingerprint OT and IoT devices on your LAN. That deep internal and operational-technology discovery is exactly where runZero leads. Resensor focuses on what is reachable from the public internet.
What does Resensor add on top of asset discovery?
Exploit-aware prioritization with CISA KEV and FIRST EPSS on every finding, plus validation evidence such as reachability re-checks, screenshots and non-destructive proof. It also covers exposed cloud data, AI services, email spoofability, typosquatted look-alike domains with takedown packets, and third-party vendor ratings, so you see not just what exists but what an attacker is most likely to exploit.
Can I use runZero and Resensor together?
Yes, and they complement each other cleanly. runZero gives you a complete asset inventory across internal, OT, IoT and cloud. Resensor gives you the external attacker view of your internet-facing surface, validated and prioritized by real-world exploitability. One answers what do we have, the other answers what can an attacker reach and what should we fix first.