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Cybersecurity · head to head

Sysdig vs Tenable Nessus

Sysdig logo

Sysdig

Cybersecurity

Cloud-native runtime security platform with real-time detection and response

From
On request
Rated
-
Full reviewWebsite
Tenable Nessus logo

Tenable Nessus

Cybersecurity

Network vulnerability scanner

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only Tenable Nessus has a free tier, so it costs nothing to try first.
  • Each has a real cost: Sysdig custom pricing requires sales contact, difficult to compare costs; Tenable Nessus nessus Professional is $4,790 for one year, sold as an annual licence rather than a per scan or usage based fee
  • They diverge on capability: Sysdig covers Real-time threat detection and response, Tenable Nessus covers Network scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Sysdig and Tenable Nessus actually diverge.

Attributes where Sysdig and Tenable Nessus differ
AttributeSysdigTenable Nessus
Starting priceOn requestFree
Pricing modelCustom pricing based on number of hosts, events processed, or time series datasubscription
Free tierNoYes
PlatformsKubernetes, Docker, AWS, GCP, Azure, Cloud-nativeWindows, Linux, Macos, Cloud
Founded20132002

Identical on both: user rating (Not yet rated), category (Cybersecurity).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Sysdig

  • Real-time threat detection and response
  • Runtime intelligence
  • AI-powered security agents
  • Vulnerability management
  • Cloud Security Posture Management
  • Container and Kubernetes security
  • Infrastructure as Code security
  • Cloud Infrastructure Entitlement Management

Only in Tenable Nessus

  • Network scanning
  • Vulnerability detection
  • Configuration assessment
  • Malware detection
  • Compliance checking
  • Cloud security assessment
  • Mobile scanning
  • API access

What people use each for

The jobs each tool is most often brought in to do.

Sysdig

  • Real-time threat detection in Kubernetes clustersnot Tenable Nessus
  • Container workload vulnerability prioritizationnot Tenable Nessus
  • Cloud security posture compliance monitoringnot Tenable Nessus
  • Infrastructure entitlement and permission analysisnot Tenable Nessus
  • AI workload security and threat remediationnot Tenable Nessus

Tenable Nessus

  • Vulnerability scanning of servers, network devices and web applicationsnot Sysdig
  • Configuration and compliance auditing against hardening benchmarksnot Sysdig
  • Point in time assessments by consultants and penetration testersnot Sysdig

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Sysdig

  • Custom pricing requires sales contact, difficult to compare costs
  • No published pricing tiers or calculator available
  • Primarily focused on cloud-native environments
  • Requires integration with existing SIEM or monitoring tools for full visibility
  • Steep learning curve for runtime security concepts

Tenable Nessus

  • Nessus Professional is $4,790 for one year, sold as an annual licence rather than a per scan or usage based fee
  • Support beyond the base entitlement costs an extra $400 per year for Advanced Support with 24x365 phone and chat access
  • The on demand training course is a separate $275 purchase for a single person for one year
  • Multi year discounts require paying for two or three years up front

Pricing, plan by plan

Sysdig

On request

No published plan breakdown. See the Sysdig review.

Tenable Nessus

Free
  • Nessus EssentialsFree
    • Up to 16 ips
    • Network scanning
    • Vulnerability assessment
  • Nessus Professional$2600/year
    • Unlimited targets
    • Enterprise features
    • Advanced analytics
  • Nessus Expert$5200/year
    • All Professional features
    • Cloud integration
    • Advanced reporting

Which should you pick?

Choose Sysdig if

  • You need real-time threat detection and response.
  • You work on Kubernetes, Docker, AWS, GCP, Azure, Cloud-native.
  • You also want runtime intelligence.
Sysdig review

Choose Tenable Nessus if

  • You need network scanning.
  • You want to start without paying.
  • You work on Windows, Linux, Macos, Cloud.
  • You also want vulnerability detection.
Tenable Nessus review

Questions people ask

Is Sysdig or Tenable Nessus better?
Neither clearly leads. Sysdig starts at On request and Tenable Nessus at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Sysdig or Tenable Nessus?
Tenable Nessus has a free tier; the other does not. Paid plans start at On request for Sysdig and Free for Tenable Nessus.
Does Sysdig or Tenable Nessus run on more platforms?
Sysdig runs on Kubernetes, Docker, AWS, GCP, Azure, Cloud-native. Tenable Nessus runs on Windows, Linux, Macos, Cloud.
Can I use Tenable Nessus for free?
Yes. Tenable Nessus has a free tier, so you can try it without paying. Sysdig starts at On request.
What is Sysdig best used for?
Sysdig is most often used for real-time threat detection in kubernetes clusters, container workload vulnerability prioritization, cloud security posture compliance monitoring, infrastructure entitlement and permission analysis. Of those, real-time threat detection in kubernetes clusters and container workload vulnerability prioritization are not what Tenable Nessus is typically brought in for.
What can Sysdig do that Tenable Nessus cannot?
Sysdig covers Real-time threat detection and response, Runtime intelligence, AI-powered security agents, Vulnerability management. Tenable Nessus covers Network scanning, Vulnerability detection, Configuration assessment, Malware detection.

Answered from the vendors’ own pages

Sysdig: How does Sysdig achieve real-time threat detection?

Sysdig uses runtime intelligence with kernel-level system visibility, capturing live system calls to detect threats at machine speed, typically within 2 seconds.

Source
Tenable Nessus: What are the three Nessus offerings?

Nessus Essentials is a free introductory offering for educators, students, and career starters, limited to 16 IPs for scanning. Nessus Professional is designed for consultants and SMBs, providing unlimited IT scans across any location. Nessus Expert is the premium offering extending Professional with web application scanning, infrastructure-as-code scanning, and external attack surface assessment up to 5 domains.

Source
Sysdig: What is runtime intelligence and how does it differ from configuration-based security?

Runtime intelligence reveals what is actually executing in cloud environments through kernel-level visibility, rather than relying on theoretical risks from configuration analysis alone.

Source
Tenable Nessus: What OS platforms does Nessus support?

Nessus runs on Debian/Kali Linux, Fedora, FreeBSD, Mac OS X, Red Hat/CentOS, SUSE Linux, Ubuntu, and various Windows versions including Server 2008, 2012, and Windows 7-10.

Source
Sysdig: What cloud platforms does Sysdig support?

Sysdig supports AWS, GCP, Azure, and IBM Cloud with multiple regional data centers across US, EU, and other regions.

Source
Tenable Nessus: Can I use Nessus to scan third-party networks as a consultant?

Yes, Tenable permits you to use Nessus to scan third-party networks. Nessus Professional is ideal for consultants.

Source
Sysdig: Does Sysdig integrate with existing security tools?

Yes, Sysdig integrates with existing SIEM and monitoring tools to provide unified security visibility across cloud infrastructure.

Source
Tenable Nessus: Can Nessus perform PCI external scanning?

Yes, you can use Nessus Professional to perform external network scans as required by the PCI DSS 11.2.2 requirement.

Source
Tenable Nessus: What additional features does Nessus Expert provide?

Web application scanning, which is dynamic application security testing (DAST) providing comprehensive visibility and insight into web application security issues; scanning code repositories for vulnerabilities; and assessing external attack surface with subdomain discovery.

Source
Tenable Nessus: What support options exist for Nessus Professional?

Standard Support includes software upgrades, patches, plugin access, and 24x7 support via chat and community portal. Advanced Support adds 24x7 phone access and committed SLAs: P1 less than 2 hours, P2 less than 4 hours, P3 less than 12 hours, P4 less than 24 hours.

Source
Tenable Nessus: How frequently are Nessus plugins updated?

Nessus plugins are updated daily, based on when vendors and security research sites publish new vulnerabilities.

Source
Tenable Nessus: How does licensing work in virtual machine environments?

Whether you are using Nessus in a physical or a virtual environment, the IP addresses or hosts that you are scanning from must be licensed.

Source
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