Nessus Professional is a commercial vulnerability assessment solution by Tenable. Semperis Purple Knight is a free vulnerability assessment solution by Semperis. Features, integrations, deployment and the company behind each one, side by side.
Vulnerability scanner for assessing networks, systems, and apps for security flaws.
Free AD, Entra ID, and Okta security assessment tool for vulnerability scanning
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Based on what each listing shows: deployment, company size, price and open source.
Nessus Professional fits if you need to run it on your own servers.
Semperis Purple Knight fits if you want a cloud product and you need a free product.
Common questions when comparing Nessus Professional vs Semperis Purple Knight for vulnerability assessment.
Nessus Professional: Vulnerability scanner for assessing networks, systems, and apps for security flaws. Built by Tenable.
Semperis Purple Knight: Free AD, Entra ID, and Okta security assessment tool for vulnerability scanning. Built by Semperis.
The table above shows where their features, integrations, deployment and company size fit differ.
Nessus Professional is made by Tenable. Semperis Purple Knight is made by Semperis. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.
Often, yes. Nessus Professional and Semperis Purple Knight are both Vulnerability Assessment products. Key differences: Nessus Professional is Commercial while Semperis Purple Knight is Free. Use the table above to see where features, deployment and company size fit differ.
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Updated 2026-11-02
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