Softwr

Cybersecurity · head to head

KnowBe4 vs Nessus

KnowBe4 logo

KnowBe4

Cybersecurity

World's largest security awareness training platform

From
$1/month
Rated
-
Full reviewWebsite
Nessus logo

Nessus

Cybersecurity

The most trusted vulnerability assessment solution

From
$4790/year
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: KnowBe4 published prices assume a three year term, so the quoted per seat rate depends on a long commitment; Nessus nessus Professional is $4,790 for one year, with no free or low cost commercial tier
  • They diverge on capability: KnowBe4 covers Security awareness training, Nessus covers Vulnerability scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which KnowBe4 and Nessus actually diverge.

Attributes where KnowBe4 and Nessus differ
AttributeKnowBe4Nessus
Starting price$1/month$4790/year
PlatformsWeb, Mobile, EmailDesktop, Api
Founded20102002

Identical on both: pricing model (subscription), free tier (No), 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 KnowBe4

  • Security awareness training
  • Phishing simulation
  • Risk assessments
  • Compliance training
  • Incident reporting
  • API access
  • Custom policies
  • Behavior analytics

Only in Nessus

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

Both cover

  • Splunk
  • Cloud deployment

What people use each for

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

KnowBe4

  • Security awareness training and simulated phishing for staffnot Nessus
  • Tracking employee susceptibility to phishing over timenot Nessus

Nessus

  • Vulnerability scanning for individual practitionersnot KnowBe4
  • Enterprise vulnerability managementnot KnowBe4
  • Web application security assessmentsnot KnowBe4

Where each one falls short

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

KnowBe4

  • Published prices assume a three year term, so the quoted per seat rate depends on a long commitment
  • Pricing is banded by seat count, and the lowest band of 25 to 50 seats pays the highest rate
  • Accounts above 1,000 seats have no published price and require a custom quote
  • Third party integrations, Compliance Plus and PhishER Plus are all separately priced per seat add ons
  • The Foundation tier carries 200 training modules against more than 1,000 on Advanced, so content volume is the main gate

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

KnowBe4

$1/month
  • Basic$1/month
    • Per user
    • Training modules
    • Phishing templates
  • Advanced$2/month
    • All Basic features
    • Advanced phishing
    • Risk assessments
  • Pro$3/month
    • All Advanced features
    • API access
    • Custom content

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 KnowBe4 if

  • You need security awareness training.
  • You work on Web, Mobile, Email.
  • You also want phishing simulation.
KnowBe4 review

Choose Nessus if

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

Questions people ask

Is KnowBe4 or Nessus better?
Neither clearly leads. KnowBe4 starts at $1/month and Nessus at $4790/year, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, KnowBe4 or Nessus?
KnowBe4 starts at $1/month and Nessus at $4790/year.
Does KnowBe4 or Nessus run on more platforms?
KnowBe4 runs on Web, Mobile, Email. Nessus runs on Desktop, Api.
What is KnowBe4 best used for?
KnowBe4 is most often used for security awareness training and simulated phishing for staff, tracking employee susceptibility to phishing over time. Of those, security awareness training and simulated phishing for staff and tracking employee susceptibility to phishing over time are not what Nessus is typically brought in for.
What can KnowBe4 do that Nessus cannot?
KnowBe4 covers Security awareness training, Phishing simulation, Risk assessments, Compliance training. Nessus covers Vulnerability scanning, Configuration auditing, Malware detection, Web application scanning. Both handle Splunk, Cloud deployment.

Answered from the vendors’ own pages

KnowBe4: What does KnowBe4 cost per employee?

KnowBe4 charges per seat per month on a subscription basis. For 51-100 employees, SAT Foundation costs $2.13/month per seat and SAT Advanced costs $3.40/month per seat. Prices decrease with larger employee counts.

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
KnowBe4: Does KnowBe4 offer a free trial?

KnowBe4 does not offer a full free version, but free tools are available separately including assessments and simulators.

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
KnowBe4: Are there add-on costs beyond the base plan?

Yes, optional add-ons include Third-Party Integrations ($1.10-$1.20/seat/month), Compliance Plus ($0.82-$0.93/seat/month), PhishER Plus ($1.15-$1.50/seat/month), and Student Edition ($0.17/seat/month).

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
KnowBe4: What currencies does KnowBe4 accept?

KnowBe4 accepts pricing in USD, AUD, BRL, CAD, EUR, GBP, SGD, and ZAR.

Source
Share

Related pages

More on KnowBe4

More on Nessus

Keep looking

Other head to heads