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Developer Tools · head to head

Keil MDK vs Tenable Nessus

Keil MDK logo

Keil MDK

Developer Tools

Microcontroller Development Kit for Arm-based devices

From
Free
Free plan
Yes
Full reviewWebsite
Tenable Nessus logo

Tenable Nessus

Cybersecurity

Network vulnerability scanner

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Keil MDK pricing for Essential and Professional subscriptions not disclosed on primary site; Tenable Nessus nessus Professional is $4,790 for one year, sold as an annual licence rather than a per scan or usage based fee
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Keil MDK and Tenable Nessus actually diverge.

Attributes where Keil MDK and Tenable Nessus differ
AttributeKeil MDKTenable Nessus
Pricing modelfreemiumsubscription
PlatformsWebWindows, Linux, Macos, Cloud
CategoryDeveloper ToolsCybersecurity
FoundedUnknown2002

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

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 Keil MDK

Nothing recorded that Tenable Nessus does not also cover.

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.

Keil MDK

  • Embedded software developmentnot Tenable Nessus
  • ARM microcontroller programmingnot Tenable Nessus
  • Professional development environmentsnot Tenable Nessus

Tenable Nessus

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

Where each one falls short

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

Keil MDK

  • Pricing for Essential and Professional subscriptions not disclosed on primary site
  • Customers must contact Arm Developer Tools store for subscription rates

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

Keil MDK

Free

No published plan breakdown. See the Keil MDK 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 Keil MDK if

  • You want to start without paying.
Keil MDK 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 Keil MDK or Tenable Nessus better?
Neither clearly leads. Keil MDK 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, Keil MDK or Tenable Nessus?
Keil MDK starts at Free and Tenable Nessus at Free.
Does Keil MDK or Tenable Nessus run on more platforms?
Keil MDK runs on Web. Tenable Nessus runs on Windows, Linux, Macos, Cloud.
Can I use Keil MDK for free?
Both have a free tier, so you can try either at no cost before committing.
What is Keil MDK best used for?
Keil MDK is most often used for embedded software development, arm microcontroller programming, professional development environments. Of those, embedded software development and arm microcontroller programming are not what Tenable Nessus is typically brought in for.
What can Keil MDK do that Tenable Nessus cannot?
Tenable Nessus covers Network scanning, Vulnerability detection, Configuration assessment, Malware detection.

Answered from the vendors’ own pages

Keil MDK: Does Keil MDK have a free version?

Yes, Keil MDK Community Edition is free for non-commercial projects. Essential and Professional editions are available as monthly or annual subscriptions.

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
Keil MDK: How much do Keil MDK paid editions cost?

Specific pricing for Essential and Professional editions is not published on the main site. Rates are available from the Arm Developer Tools store or by contacting Arm sales.

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
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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