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Cybersecurity · head to head

Authy vs Tenable Nessus

Authy logo

Authy

Cybersecurity

Twilio's free authenticator app with encrypted cloud backup, mobile only since the desktop clients were withdrawn in 2024.

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: Authy there is no export function for stored TOTP secrets, so moving to a different authenticator means disabling and re-enrolling two-factor authentication on every account individually, which is the reason most users stay rather than a reason anyone should choose it.; 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: Authy covers Encrypted cloud backup, Tenable Nessus covers Network scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Authy and Tenable Nessus actually diverge.

Attributes where Authy and Tenable Nessus differ
AttributeAuthyTenable Nessus
Pricing modelfreesubscription
PlatformsWebWindows, Linux, Macos, Cloud
FoundedUnknown2002

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 Authy

  • Encrypted cloud backup
  • Multi-device sync
  • Standard TOTP
  • Offline code generation
  • App lock
  • Multi-device toggle
  • Token organisation
  • Free with no account tier

Only in Tenable Nessus

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

What people use each for

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

Authy

  • An individual who wants two-factor authentication on personal accounts and needs it to survive losing or replacing a phonenot Tenable Nessus
  • A small team sharing access to a service account where the same tokens must be available on more than one handsetnot Tenable Nessus
  • Replacing SMS-based codes with TOTP for someone who would abandon two-factor entirely if recovery were difficultnot Tenable Nessus
  • Consolidating tokens scattered across several apps onto one device list with recognisable names and iconsnot Tenable Nessus

Tenable Nessus

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

Where each one falls short

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

Authy

  • There is no export function for stored TOTP secrets, so moving to a different authenticator means disabling and re-enrolling two-factor authentication on every account individually, which is the reason most users stay rather than a reason anyone should choose it.
  • The Windows, macOS and Linux desktop applications were discontinued in 2024 and stopped working, so any workflow that depended on copying codes on a computer now requires a phone in hand, and users who held tokens only on a desktop client had to restore from backup or re-enrol.
  • The account is keyed to a phone number, so an attacker who takes over that number through a SIM swap can begin the device registration flow, and the only remaining control is the backup password that most users set once and cannot recall.
  • In 2024 an unauthenticated Twilio endpoint allowed attackers to confirm which numbers from a supplied list were registered Authy accounts, exposing around 33 million phone numbers, which disclosed no codes but handed phishers a validated list of people known to use two-factor authentication.
  • It is a free consumer application inside a company that has already retired the paid Authy developer API it once supported, so it carries no revenue of its own, and users should treat its continued existence as a business decision rather than a roadmap commitment.

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

Authy

Free

No published plan breakdown. See the Authy review.

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 Authy if

  • You need encrypted cloud backup.
  • You want to start without paying.
  • You also want multi-device sync.
Authy 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 Authy or Tenable Nessus better?
Neither clearly leads. Authy 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, Authy or Tenable Nessus?
Authy starts at Free and Tenable Nessus at Free.
Does Authy or Tenable Nessus run on more platforms?
Authy runs on Web. Tenable Nessus runs on Windows, Linux, Macos, Cloud.
Can I use Authy for free?
Both have a free tier, so you can try either at no cost before committing.
What is Authy best used for?
Authy is most often used for an individual who wants two-factor authentication on personal accounts and needs it to survive losing or replacing a phone, a small team sharing access to a service account where the same tokens must be available on more than one handset, replacing sms-based codes with totp for someone who would abandon two-factor entirely if recovery were difficult, consolidating tokens scattered across several apps onto one device list with recognisable names and icons. Of those, an individual who wants two-factor authentication on personal accounts and needs it to survive losing or replacing a phone and a small team sharing access to a service account where the same tokens must be available on more than one handset are not what Tenable Nessus is typically brought in for.
What can Authy do that Tenable Nessus cannot?
Authy covers Encrypted cloud backup, Multi-device sync, Standard TOTP, Offline code generation. Tenable Nessus covers Network scanning, Vulnerability detection, Configuration assessment, Malware detection.

Answered from the vendors’ own pages

Authy: Is Authy still supported?

The mobile apps for iOS and Android are still available and functional. The desktop applications were withdrawn in 2024 and the Authy developer API has been retired in favour of Twilio Verify, so the surrounding product has been shrinking.

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
Authy: Can I export my tokens?

No. There is no export of the underlying secrets, by design. Migrating to another authenticator means going to each service, disabling two-factor authentication and setting it up again with the new app.

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
Authy: What happened to the desktop app?

Twilio announced its discontinuation in March 2024 and the applications stopped working later that year. There is no replacement desktop client; the mobile apps are the product now.

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
Authy: Is multi-device sync safe to leave on?

It is the feature most worth understanding. Leaving new device registration enabled means anyone who controls your phone number can attempt to add a device. The usual advice is to turn the multi-device setting off once your devices are registered and turn it on only when you need to add one.

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
Authy: What if I lose my phone and forget the backup password?

The secrets are encrypted with that password and Twilio does not hold it, so they cannot be recovered. You would fall back to each individual service's account recovery process, which is exactly the situation the backup was meant to avoid.

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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