Nuclei review
A flexible, free scanner for teams that want control over templates and execution.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Nuclei is a high-performance, open-source vulnerability scanner from ProjectDiscovery. It is designed for security engineers who need customizable detection across web applications, APIs, networks, DNS, SSL, JavaScript, code, WebSocket, and other supported targets. The standalone CLI accepts targets from files, standard input, or direct arguments, while YAML templates let teams run community checks or define their own. Authenticated testing supports secret files, headers, cookies, tokens, and login templates, making the scanner suitable for controlled testing of applications and infrastructure.
The core product is free and open source, with a self-hosted deployment model. ProjectDiscovery also documents Pro and Enterprise cloud editions built on Nuclei OSS for team-based scanning and reporting. The scanner fits delivery workflows through CI/CD integration and connects with Jira, Splunk, GitHub, Elastic, and GitLab. OpenAPI and Swagger specification testing extends its API coverage, while JSON, JSONL, Markdown, SARIF, and PDF outputs support different reporting and pipeline needs. Parallel processing and request clustering are useful for teams that need to run template-driven checks across larger target sets.
Nuclei’s main strength is breadth combined with control: teams can tune detection through YAML, use authenticated scans, and cover multiple protocols from one command-line tool. Its main trade-off is that the experience is centered on templates and self-hosted execution, not verified application crawling. JavaScript template execution is documented, while JavaScript crawling is not part of the documented scope here. Choose Nuclei when customizable checks, automation, and integration flexibility matter most. Teams seeking a managed scanner focused on deeper application-crawling workflows should consider a different product.
Nuclei pros and cons
- Where it wins
- Custom YAML templates and an automatically updated community library
- Authenticated scans, API specification testing, and parallel processing
- CI/CD support, broad protocols, and JSON, SARIF, PDF, and other outputs
- Where it doesn't
- Primarily a standalone self-hosted CLI rather than a managed application
- Template-driven coverage provides less verified application-crawling depth
- ProjectDiscovery cloud editions are separate from the open-source scanner
Nuclei fact sheet, pricing and score →
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