# Action1 Free Initial Vulnerability Assessment vs Nessus Professional: side-by-side comparison (2026) [Action1 Free Initial Vulnerability Assessment](https://cybersectools.com/tools/action1-free-initial-vulnerability-assessment) is a commercial [vulnerability assessment](https://cybersectools.com/categories/vulnerability-assessment) solution by [Action1](https://cybersectools.com/companies/action1). [Nessus Professional](https://cybersectools.com/tools/nessus-professional) is a commercial [vulnerability assessment](https://cybersectools.com/categories/vulnerability-assessment) solution by [Tenable](https://cybersectools.com/companies/tenable). Features, integrations, deployment and the company behind each one, side by side. ## Side-by-side comparison | | Action1 Free Initial Vulnerability Assessment | Nessus Professional | |---|---|---| | Pricing model | Commercial | Commercial | | Category | Vulnerability Assessment | Vulnerability Assessment | | Verified | No | No | | Deployment type | Cloud | On-Premises | | Company size fit | Startup, SMB, Mid-Market, Enterprise | Startup, SMB, Mid-Market, Enterprise | | Company | Action1 | Tenable | | Headquarters | – | – | ### Use cases and capabilities | | Action1 Free Initial Vulnerability Assessment | Nessus Professional | |---|---|---| | Patch Management | Yes | – | | Third Party Security | Yes | – | | Windows Security | Yes | – | | Vulnerability | – | Yes | | Security Scanning | – | Yes | | CVE | – | Yes | | Penetration Testing Framework | – | Yes | | NIST | – | Yes | | PCI DSS | – | Yes | | CIS | – | Yes | | Network Scanning | – | Yes | | VAPT | – | Yes | ### Core features **Action1 Free Initial Vulnerability Assessment** 10 features listed. Sign in on the page to see them. **Nessus Professional** 10 features listed. Sign in on the page to see them. ### Integrations **Action1 Free Initial Vulnerability Assessment** 5 integrations listed. Sign in on the page to see them. **Nessus Professional** No integrations listed. ## Which one fits you Based on what each listing shows: deployment, company size, price and open source. - [Action1 Free Initial Vulnerability Assessment](https://cybersectools.com/tools/action1-free-initial-vulnerability-assessment) fits if you want a cloud product. - [Nessus Professional](https://cybersectools.com/tools/nessus-professional) fits if you need to run it on your own servers. ## Action1 Free Initial Vulnerability Assessment vs Nessus Professional FAQ Common questions when comparing Action1 Free Initial Vulnerability Assessment vs Nessus Professional for vulnerability assessment. ### What is the difference between Action1 Free Initial Vulnerability Assessment and Nessus Professional? **Action1 Free Initial Vulnerability Assessment**: Free vulnerability assessment for unlimited endpoints with patching capabilities. Built by Action1. **Nessus Professional**: Vulnerability scanner for assessing networks, systems, and apps for security flaws. Built by Tenable. The table above shows where their features, integrations, deployment and company size fit differ. ### Who makes Action1 Free Initial Vulnerability Assessment and Nessus Professional? **Action1 Free Initial Vulnerability Assessment** is made by Action1. **Nessus Professional** is made by Tenable. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit. ### Is Action1 Free Initial Vulnerability Assessment a good alternative to Nessus Professional? Often, yes. Action1 Free Initial Vulnerability Assessment and Nessus Professional are both Vulnerability Assessment products. Use the table above to see where features, deployment and company size fit differ. ## Related comparisons - [Action1 Free Initial Vulnerability Assessment vs Halo Security Server Scanning](https://cybersectools.com/compare/action1-free-initial-vulnerability-assessment-vs-halo-security-server-scanning) - [Action1 Free Initial Vulnerability Assessment vs Webray RayScan](https://cybersectools.com/compare/action1-free-initial-vulnerability-assessment-vs-webray-rayscan) - [Action1 Free Initial Vulnerability Assessment vs Zentara AVAS](https://cybersectools.com/compare/action1-free-initial-vulnerability-assessment-vs-zentara-avas) - [Nessus Professional vs Halo Security Server Scanning](https://cybersectools.com/compare/halo-security-server-scanning-vs-nessus-professional) - [Nessus Professional vs Webray RayScan](https://cybersectools.com/compare/nessus-professional-vs-webray-rayscan) - [Nessus Professional vs Zentara AVAS](https://cybersectools.com/compare/nessus-professional-vs-zentara-avas) ## Alternatives to each - [See all Action1 Free Initial Vulnerability Assessment alternatives](https://cybersectools.com/alternatives/action1-free-initial-vulnerability-assessment) - [See all Nessus Professional alternatives](https://cybersectools.com/alternatives/nessus-professional) --- Source: https://cybersectools.com/compare/action1-free-initial-vulnerability-assessment-vs-nessus-professional For AI agents: each product above has its own Markdown page (add .md to its URL, for example https://cybersectools.com/tools/action1-free-initial-vulnerability-assessment.md). Every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md. More on Action1 Free Initial Vulnerability Assessment and Nessus Professional: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md