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Cybersecurity · head to head

Ory Kratos vs Tenable Nessus

Ory Kratos logo

Ory Kratos

Cybersecurity

Headless identity and user management API

From
Free
Rated
-
Full reviewWebsite
Tenable Nessus logo

Tenable Nessus

Cybersecurity

Network vulnerability scanner

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Ory Kratos headless means you build every screen, which is significant work compared with a hosted login page; 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: Ory Kratos covers Headless API, Tenable Nessus covers Network scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Ory Kratos and Tenable Nessus actually diverge.

Attributes where Ory Kratos and Tenable Nessus differ
AttributeOry KratosTenable Nessus
Pricing modelOpen-source self-hosted, with a paid managed networksubscription
PlatformsLinux, Docker, Kubernetes, Self-hostedWindows, Linux, Macos, Cloud
FoundedUnknown2002

Identical on both: starting price (Free), free tier (Yes), 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 Ory Kratos

  • Headless API
  • Self-service flows
  • Multi-factor authentication
  • Pluggable identity schemas

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.

Ory Kratos

  • Products needing complete control over the look and flow of authenticationnot Tenable Nessus
  • Applications that must not hand user identity data to a third partynot Tenable Nessus
  • Teams building identity as infrastructure across several servicesnot Tenable Nessus

Tenable Nessus

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

Where each one falls short

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

Ory Kratos

  • Headless means you build every screen, which is significant work compared with a hosted login page
  • More moving parts than a monolithic IAM: Kratos handles identity, and OAuth2 needs Ory Hydra alongside
  • Documentation assumes real familiarity with identity concepts and is not a gentle introduction
  • Self-hosting identity carries the security and availability burden that hosted providers absorb

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

Ory Kratos

Free
  • Self-hostedFree
    • Full identity server
    • All flows
    • Community support

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 Ory Kratos if

  • You need headless api.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want self-service flows.
Ory Kratos 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 Ory Kratos or Tenable Nessus better?
Neither clearly leads. Ory Kratos starts at Free and Tenable Nessus at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Ory Kratos or Tenable Nessus?
Ory Kratos starts at Free and Tenable Nessus at Free.
Does Ory Kratos or Tenable Nessus run on more platforms?
Ory Kratos runs on Linux, Docker, Kubernetes, Self-hosted. Tenable Nessus runs on Windows, Linux, Macos, Cloud.
Can I use Ory Kratos for free?
Both have a free tier, so you can try either at no cost before committing.
What is Ory Kratos best used for?
Ory Kratos is most often used for products needing complete control over the look and flow of authentication, applications that must not hand user identity data to a third party, teams building identity as infrastructure across several services. Of those, products needing complete control over the look and flow of authentication and applications that must not hand user identity data to a third party are not what Tenable Nessus is typically brought in for.
What can Ory Kratos do that Tenable Nessus cannot?
Ory Kratos covers Headless API, Self-service flows, Multi-factor authentication, Pluggable identity schemas. Tenable Nessus covers Network scanning, Vulnerability detection, Configuration assessment, Malware detection.

Answered from the vendors’ own pages

Ory Kratos: Is Ory Kratos free?

Yes, open source and free to self-host. Ory Network is a paid managed service.

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
Ory Kratos: What does headless mean here?

Kratos provides identity flows as APIs and no user interface. You build the login, registration and recovery screens yourself.

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
Ory Kratos: Does Kratos do OAuth2?

No. Kratos handles user identity; OAuth2 and OpenID Connect provider functionality is Ory Hydra, a separate component.

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
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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