The short answer
AvalonX and Tenable Nessus are tools from different categories. Our data shows little overlap between them. Neither has a clear edge on the figures we track (entry price, review ratings, integrations, frameworks, customers). Best fit: AvalonX for small and midsize businesses needing recurring testing without an in-house red team and Tenable Nessus for security teams running recurring infrastructure vulnerability assessments. Shortlist on fit, then compare quotes for the same scope.
Which should you choose?
Choose AvalonX if…
- you're among small and midsize businesses needing recurring testing without an in-house red team
- you're among security teams wanting verified findings and retesting rather than raw scanner output
- you're among companies preparing SOC 2, ISO 27001, PCI DSS or HIPAA/HITECH evidence
- this Tenable Nessus drawback matters to you: the annual license is a substantial cost for small security teams
Choose Tenable Nessus if…
- you're among security teams running recurring infrastructure vulnerability assessments
- you're among consultants conducting repeatable client security scans
- you're among organizations needing compliance and configuration audit checks
- this AvalonX drawback matters to you: public plans cap included coverage at 10 targets
At a glance
| Attribute | AvalonX | Tenable Nessus |
|---|---|---|
| Starting price | From $249/mopricing as of Nov 2026 | From $4,790/yrpricing as of Oct 2026 |
| Pricing model | Monthly subscription, published tiers | Annual subscription license |
| Free trial | Free external read-only test; no paid-plan trial is publicly specified. | Free trial available; Nessus Expert offers a seven-day free upgrade from Professional. |
| Founded | Not published | 2002 |
| Headquarters | Alpharetta, GA | Columbia, MD |
| Funding | Up to $10M committed facility from Ridown Capital | Not published |
| Frameworks | SOC 2 Type II, ISO/IEC 27001:2022, PCI DSS v4.0, HIPAA/HITECH | Configuration, compliance and security audits |
| Coverage | Continuous penetration testing and vulnerability scanning for up to 10 targets per plan | 336K+ CVEs covered |
| Integrations | Not published | Security and IT workflow integrations available through Tenable ecosystem and connectors |
| Customers | Not published | 40,000+ worldwide |
| Rating | Not published | 4.5/5 on G2 (304 reviews) |
| Focus | Continuous penetration testing | Vulnerability assessment |
Figures are as published by each vendor or review site on the verification date. "Leads" marks the stronger published figure; it isn't a recommendation on its own.
Where each one leads
Neither tool has a clear edge on the figures we can compare directly (entry price, review rating, integrations, frameworks, customers, free trial).
Pricing compared
AvalonX pricing
From $249/mo · pricing as of Nov 2026
- Essentials$249/mo
Quarterly testing, up to 10 targets, scanning, verified findings, remediation guidance, AAA Tested badge
- Monthly testing$599/mo
Monthly testing, up to 10 targets, scanning, verified findings, remediation guidance, AAA Tested badge
- 360$899/mo
Weekly testing, up to 10 targets, scanning, verified findings, remediation guidance, AAA Tested badge
Published plans start at $249 per month and cover up to 10 targets. All plans combine scheduled penetration testing with continuous vulnerability scanning, verified findings and remediation guidance.
Free trial: Free external read-only test; no paid-plan trial is publicly specified.
Tenable Nessus pricing
From $4,790/yr · pricing as of Oct 2026
- Nessus Professional$4,790/year
One-year license
Real-time vulnerability updates, unlimited vulnerability scanning, pre-built configuration and compliance policies, vulnerability scoring, configurable reports and flexible deployment.
- Nessus Expert$6,790/year
One-year license
Everything in Professional, plus web application scanning for 5 FQDNs and external attack surface discovery scanning for 5 domains.
Nessus Professional costs $4,790 for one year and Nessus Expert costs $6,790 for one year. Multi-year licenses are available at $9,330.95 for Professional for two years and $13,637.54 for three years; Expert costs $13,208.13 for two years and $19,304.19 for three years. Advanced Support and on-demand training are optional paid add-ons.
Free trial: Free trial available; Nessus Expert offers a seven-day free upgrade from Professional.
Key capabilities
AvalonX
- Autonomous penetration testing. Artemis coordinates agents across reconnaissance, enumeration, exploitation, lateral movement and reporting.
- Attack-surface discovery. The platform continuously discovers external assets and shows how the authorised attack surface changes.
- Attack-path reasoning. Aether connects weaknesses to model realistic routes an attacker could use to compromise a business.
- Validated findings. Testing validates exploitability and provides evidence, reproduction steps, impact and remediation guidance.
- Remediation and retesting. Teams can request retests after fixes and verify whether vulnerabilities have closed.
- Compliance evidence mapping. Findings map to SOC 2 Type II, ISO 27001:2022, PCI DSS v4.0 and HIPAA/HITECH requirements.
- Controlled engagement workflow. Customers define scope, exclusions, windows and escalation contacts, with pause controls and audit trails.
Tenable Nessus
- Vulnerability scanning. Identifies software flaws, missing patches and misconfigurations across operating systems, devices and applications.
- Risk prioritization. Scores findings with CVSS v4, EPSS and VPR signals to help teams focus on the most consequential vulnerabilities.
- Compliance auditing. Provides pre-built policies and checks for configuration, compliance and security audits.
- Web application scanning. Nessus Expert scans five web application FQDNs, with the option to add more.
- Attack surface discovery. Nessus Expert scans five external domains to discover externally exposed attack-surface assets.
- Configurable reporting. Produces configurable reports that communicate findings and support remediation planning.
- Flexible deployment. Supports use anywhere through flexible deployment options and unlimited vulnerability assessments.
Pros and cons
AvalonX
Pros
- Published pricing starts at $249 per month.
- Autonomous testing is paired with human verification.
- Same-day findings, remediation guidance and retesting shorten the fix-and-verify loop.
- Explicit scope boundaries, testing windows, pause controls and audit trails support safer testing.
Cons
- Public plans cap included coverage at 10 targets.
- The service supports compliance evidence but does not certify an organization.
- Publicly documented integrations and API access are limited.
- Penetration testing is quarterly, monthly or weekly by plan; only vulnerability scanning runs continuously.
Tenable Nessus
Pros
- Unlimited assessments are included in both paid license tiers.
- CVSS v4, EPSS and VPR scoring supports practical prioritization.
- Pre-built compliance and configuration policies speed audit work.
- Expert extends core scanning with web application and external-domain discovery.
Cons
- The annual license is a substantial cost for small security teams.
- Web application and external-domain scanning are limited to five targets initially in Expert.
- Advanced support and training cost extra.
- Broader exposure-management workflows may require additional Tenable products.
How they're similar
Our data shows little direct overlap between them.
How they differ
- Focus
- AvalonX: Continuous penetration testing
- Tenable Nessus: Vulnerability assessment
- Pricing model
- AvalonX: Monthly subscription, published tiers
- Tenable Nessus: Annual subscription license
- Starting price
- AvalonX: From $249/mo
- Tenable Nessus: From $4,790/yr
- Headquarters
- AvalonX: Alpharetta, GA
- Tenable Nessus: Columbia, MD
- Listed only for this tool
- AvalonX: SOC 2 Type II, ISO 27001, PCI DSS v4.0, HIPAA/HITECH, Penetration testing, Vulnerability scanning +3 more
- Tenable Nessus: Vulnerability assessment, Network security, Configuration audits, Compliance audits, CVSS, EPSS +4 more
Frequently asked questions
Is AvalonX cheaper than Tenable Nessus?
+
The published prices can't be compared directly (they are quote-based, use different billing units, or aren't published), so request quotes for the same scope. AvalonX: From $249/mo (monthly subscription, published tiers). Tenable Nessus: From $4,790/yr (annual subscription license). (AvalonX pricing pricing as of Nov 2026; Tenable Nessus pricing pricing as of Oct 2026.) Total cost depends on plan, company size and add-ons.
Which is better for startups, AvalonX or Tenable Nessus?
+
AvalonX's published positioning doesn't single out startups; its first best-fit group is "Small and midsize businesses needing recurring testing without an in-house red team". Tenable Nessus's published positioning doesn't single out startups; its first best-fit group is "Security teams running recurring infrastructure vulnerability assessments". Neither answer replaces a quote for your headcount and scope.
Can I switch from AvalonX to Tenable Nessus?
+
Yes. They are separate products, so switching means setting up Tenable Nessus and reconnecting your systems. Check your AvalonX contract term and renewal date before you commit. Tenable Nessus offers a free trial: Free trial available; Nessus Expert offers a seven-day free upgrade from Professional. Data migration tooling isn't covered in our sources, so ask Tenable Nessus whether it can import your AvalonX data.
Does AvalonX or Tenable Nessus have more integrations?
+
AvalonX: not published; Tenable Nessus: Security and IT workflow integrations available through Tenable ecosystem and connectors. Vendor counts are self-reported and define "integration" differently, so check that the specific systems you use are supported.
How do AvalonX and Tenable Nessus reviews compare?
+
AvalonX: no rating in our data; Tenable Nessus scores 4.5/5 from 304 reviews on G2. Ratings are third-party review-site data, not our own testing.
Do AvalonX and Tenable Nessus offer a free trial?
+
AvalonX: Free external read-only test; no paid-plan trial is publicly specified. Tenable Nessus: Free trial available; Nessus Expert offers a seven-day free upgrade from Professional.
Go deeper
AvalonX
Compliance
Tenable Nessus
Audit & Risk
Sources
Vendors change pricing and features often, so confirm with each vendor before buying. How we research
Work at one of these companies or spot something out of date? Suggest a correction. We check every report against a public source and update the page, usually within a few days.