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Cybersecurity · head to head

Avast One vs Tenable Nessus

Avast One logo

Avast One

Cybersecurity

All-in-one protection for your digital life

From
Free
Rated
-
Full reviewWebsite
Tenable Nessus logo

Tenable Nessus

Cybersecurity

Network vulnerability scanner

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Avast One ransomware and Wi-Fi vulnerability protection only on paid plans; Tenable Nessus nessus Professional is $4,790 for one year, sold as an annual licence rather than a per scan or usage based fee
  • They diverge on capability: Avast One covers Antivirus, Tenable Nessus covers Network scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Avast One and Tenable Nessus actually diverge.

Attributes where Avast One and Tenable Nessus differ
AttributeAvast OneTenable Nessus
Pricing modelUnknownsubscription
PlatformsWindows, macOS, iOS, AndroidWindows, Linux, Macos, Cloud
Founded19882002

Identical on both: starting price (Free), free tier (Yes), 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 Avast One

  • Antivirus
  • Firewall
  • VPN
  • Data breach monitoring
  • Email Guardian
  • Webcam Shield
  • Ransomware Shield
  • Performance optimization

Only in Tenable Nessus

  • Network scanning
  • Vulnerability detection
  • Configuration assessment
  • Malware detection
  • Compliance checking
  • Cloud security assessment
  • Mobile scanning
  • API access

Both cover

  • Cloud deployment

What people use each for

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

Avast One

  • Antivirusnot Tenable Nessus
  • Internet Securitynot Tenable Nessus
  • Privacy Toolsnot Tenable Nessus

Tenable Nessus

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

Where each one falls short

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

Avast One

  • Ransomware and Wi-Fi vulnerability protection only on paid plans
  • Free plan VPN is limited, no data breakthrough monitoring
  • Rebuilt app in May 2026 may have stability issues

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

Avast One

Free
  • FreeFree
    • Antivirus
    • Limited VPN
    • Privacy tools
  • Silver$2.99/month
    • Enhanced antivirus
    • VPN
    • Device cleanup
  • Premium$4.19/month
    • Full antivirus
    • VPN with 55 servers
    • Password manager
  • Premium Plus$11.67/month
    • All Premium features
    • 30 devices covered

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 Avast One if

  • You need antivirus.
  • You want to start without paying.
  • You work on Windows, macOS, iOS, Android.
  • You also want firewall.
Avast One 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 Avast One or Tenable Nessus better?
Neither clearly leads. Avast One 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, Avast One or Tenable Nessus?
Avast One starts at Free and Tenable Nessus at Free.
Does Avast One or Tenable Nessus run on more platforms?
Avast One runs on Windows, macOS, iOS, Android. Tenable Nessus runs on Windows, Linux, Macos, Cloud.
Can I use Avast One for free?
Both have a free tier, so you can try either at no cost before committing.
What is Avast One best used for?
Avast One is most often used for antivirus, internet security, privacy tools. Of those, antivirus and internet security are not what Tenable Nessus is typically brought in for.
What can Avast One do that Tenable Nessus cannot?
Avast One covers Antivirus, Firewall, VPN, Data breach monitoring. Tenable Nessus covers Network scanning, Vulnerability detection, Configuration assessment, Malware detection. Both handle Cloud deployment.

Answered from the vendors’ own pages

Avast One: Is Avast One free?

Yes. Avast One offers a free tier with antivirus, VPN (limited), and privacy tools. Paid plans start at $2.99/month for Silver and $4.19/month for Premium covering up to 5 devices.

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
Avast One: What does Avast One include?

Avast One provides antivirus, VPN, password manager, device cleanup, Wi-Fi security, data breach monitoring, and protection against AI-generated scams and deepfakes.

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
Avast One: Does Avast One have ransomware protection?

Ransomware protection is available only on paid plans, not the free tier. Free users get antivirus and basic protection only.

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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