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Developer Tools · head to head

Keil MDK vs Nessus

Keil MDK logo

Keil MDK

Developer Tools

Microcontroller Development Kit for Arm-based devices

From
Free
Free plan
Yes
Full reviewWebsite
Nessus logo

Nessus

Cybersecurity

The most trusted vulnerability assessment solution

From
$4790/year
Free plan
No
Full reviewWebsite

The short version

  • Only Keil MDK has a free tier, so it costs nothing to try first.
  • Each has a real cost: Keil MDK pricing for Essential and Professional subscriptions not disclosed on primary site; Nessus nessus Professional is $4,790 for one year, with no free or low cost commercial tier
  • Prices and features above were last checked on 30 August 2026.

Where they differ

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

Attributes where Keil MDK and Nessus differ
AttributeKeil MDKNessus
Starting priceFree$4790/year
Pricing modelfreemiumsubscription
Free tierYesNo
PlatformsWebDesktop, Api
CategoryDeveloper ToolsCybersecurity
FoundedUnknown2002

Identical on both: 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 Nessus does not also cover.

Only in Nessus

  • Vulnerability scanning
  • Configuration auditing
  • Malware detection
  • Web application scanning
  • Cloud scanning
  • Compliance checks
  • Patch auditing
  • Pre-built policies

What people use each for

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

Keil MDK

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

Nessus

  • Vulnerability scanning for individual practitionersnot Keil MDK
  • Enterprise vulnerability managementnot Keil MDK
  • Web application security assessmentsnot 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

Nessus

  • Nessus Professional is $4,790 for one year, with no free or low cost commercial tier
  • Multi year terms are the only discount route, at $9,330.95 for two years and $13,637.54 for three
  • It is a single user scanner, so team workflows mean migrating to another Tenable product
  • Tenable One vulnerability management is priced separately, starting at $3,500 a year for 100 assets

Pricing, plan by plan

Keil MDK

Free

No published plan breakdown. See the Keil MDK review.

Nessus

$4790/year
  • Nessus Professional$4790/year
    • 1 year license
    • Best for individual security professionals
  • Nessus Professional 2-Year$9330.95/2 years
    • 2 year license with discounted rate vs. annual
  • Nessus Professional 3-Year$13637.54/3 years
    • 3 year license with discounted rate vs. annual
  • Nessus Expert$6790/year
    • 1 year license
    • Enhanced capabilities vs. Professional

Which should you pick?

Choose Keil MDK if

  • You want to start without paying.
Keil MDK review

Choose Nessus if

  • You need vulnerability scanning.
  • You work on Desktop, Api.
  • You also want configuration auditing.
Nessus review

Questions people ask

Is Keil MDK or Nessus better?
Neither clearly leads. Keil MDK starts at Free and Nessus at $4790/year, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Keil MDK or Nessus?
Keil MDK has a free tier; the other does not. Paid plans start at Free for Keil MDK and $4790/year for Nessus.
Does Keil MDK or Nessus run on more platforms?
Keil MDK runs on Web. Nessus runs on Desktop, Api.
Can I use Keil MDK for free?
Yes. Keil MDK has a free tier, so you can try it without paying. Nessus starts at $4790/year.
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 Nessus is typically brought in for.
What can Keil MDK do that Nessus cannot?
Nessus covers Vulnerability scanning, Configuration auditing, Malware detection, Web application scanning.

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
Nessus: What is the cheapest Nessus option?

Nessus Professional starts at $4,790 per year for a 1-year license. Multi-year commitments offer discounts, with 2-year licenses at $9,330.95 and 3-year licenses at $13,637.54.

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
Nessus: What is the difference between Nessus Professional and Expert?

Nessus Expert costs $6,790 per year for a 1-year license (compared to $4,790 for Professional) and includes enhanced capabilities. Multi-year rates are available at discounted prices.

Source
Nessus: Does Nessus offer optional support or training?

Yes, Nessus offers add-on services: Advanced Support at $400/year provides 24x365 access to phone, email, community, and chat support. On-Demand Training costs $275/year for Fundamentals course access or $385/year for both Fundamentals and Advanced courses.

Source
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