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Cybersecurity · head to head

Microsoft Sentinel vs Nessus

Microsoft Sentinel logo

Microsoft Sentinel

Cybersecurity

Cloud-native SIEM and SOAR solution

From
Free
Rated
-
Full reviewWebsite
Nessus logo

Nessus

Cybersecurity

The most trusted vulnerability assessment solution

From
$4790/year
Rated
-
Full reviewWebsite

The short version

  • Only Microsoft Sentinel has a free tier, so it costs nothing to try first.
  • Each has a real cost: Microsoft Sentinel billing is driven by the volume of log data ingested per day, so cost scales with log noise rather than with users or protected assets; Nessus nessus Professional is $4,790 for one year, with no free or low cost commercial tier
  • They diverge on capability: Microsoft Sentinel covers AI-powered analytics, Nessus covers Vulnerability scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Microsoft Sentinel and Nessus actually diverge.

Attributes where Microsoft Sentinel and Nessus differ
AttributeMicrosoft SentinelNessus
Starting priceFree$4790/year
Pricing modelusage-basedsubscription
Free tierYesNo
PlatformsWeb, ApiDesktop, Api
Founded19752002

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 Microsoft Sentinel

  • AI-powered analytics
  • Fusion detection
  • UEBA
  • Automated response playbooks
  • Threat intelligence
  • Hunting queries
  • Workbooks
  • Incident management

Only in Nessus

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

Both cover

  • AWS
  • Google Cloud
  • ServiceNow

What people use each for

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

Microsoft Sentinel

  • Cloud-based security information and event management (SIEM)not Nessus
  • Extended detection and response (XDR) across enterprise infrastructurenot Nessus
  • Data ingestion and long-term security analyticsnot Nessus

Nessus

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

Where each one falls short

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

Microsoft Sentinel

  • Billing is driven by the volume of log data ingested per day, so cost scales with log noise rather than with users or protected assets
  • Commitment tier discounts require reserving daily ingestion capacity in advance, and a tier cannot be downgraded until 31 days have passed
  • Commitment tiers start at 100 GB per day, above what smaller estates ingest
  • Charges for Log Analytics, Logic Apps and Machine Learning are billed separately on top of Sentinel itself
  • The free allowance is only up to 5 MB per user per day for selected Microsoft 365 security logs
  • Promotional commitment pricing is time limited and locks in only until a stated end date

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

Microsoft Sentinel

Free
  • Pay-As-You-Go$2.46/day
    • Per GB ingested
    • 90-day retention
    • First 31 days free for new workspaces
  • Commitment TiersFree
    • 100GB to 50TB tiers
    • Up to 65% discount
    • Predictable billing
  • Microsoft 365 E5Free
    • Free data ingestion for M365 logs
    • Bundled with E5 license

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 Microsoft Sentinel if

  • You need ai-powered analytics.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want fusion detection.
Microsoft Sentinel review

Choose Nessus if

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

Questions people ask

Is Microsoft Sentinel or Nessus better?
Neither clearly leads. Microsoft Sentinel 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, Microsoft Sentinel or Nessus?
Microsoft Sentinel has a free tier; the other does not. Paid plans start at Free for Microsoft Sentinel and $4790/year for Nessus.
Does Microsoft Sentinel or Nessus run on more platforms?
Microsoft Sentinel runs on Web, Api. Nessus runs on Desktop, Api.
Can I use Microsoft Sentinel for free?
Yes. Microsoft Sentinel has a free tier, so you can try it without paying. Nessus starts at $4790/year.
What is Microsoft Sentinel best used for?
Microsoft Sentinel is most often used for cloud-based security information and event management (siem), extended detection and response (xdr) across enterprise infrastructure, data ingestion and long-term security analytics. Of those, cloud-based security information and event management (siem) and extended detection and response (xdr) across enterprise infrastructure are not what Nessus is typically brought in for.
What can Microsoft Sentinel do that Nessus cannot?
Microsoft Sentinel covers AI-powered analytics, Fusion detection, UEBA, Automated response playbooks. Nessus covers Vulnerability scanning, Configuration auditing, Malware detection, Web application scanning. Both handle AWS, Google Cloud, ServiceNow.

Answered from the vendors’ own pages

Microsoft Sentinel: How is Microsoft Sentinel pricing calculated?

Microsoft Sentinel uses a pay-as-you-go usage-based model where you pay only for data ingested, stored, and consumed. Flexible commitment tiers are available to reduce total cost of ownership, with specific rates not published on the public pricing page. Source: https://www.microsoft.com/security/business/siem-and-xdr/microsoft-sentinel/

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
Microsoft Sentinel: Does Microsoft Sentinel require an Azure subscription?

Yes, Microsoft Sentinel requires a Microsoft Azure subscription to operate. Pricing is handled through Azure and varies based on data consumption and the commitment tier you select. Source: https://www.microsoft.com/security/business/siem-and-xdr/microsoft-sentinel/

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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