Free
OWASP ZAP
Open SourceReference & Standards · Security
Open-source web app security scanner for finding vulnerabilities in your own apps.
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Discover the 15 best open-source tools for security. Community-driven, transparent source code with permissive licenses. Curated, compared, and updated for developers.
| Tool | Pricing | Platforms | Top Strength | Link |
|---|---|---|---|---|
| OWASP ZAP | free | desktop | Open-source web app security scanner for finding vulnerabilities in your own apps. | Details → |
| Mozilla SSL Config Generator | free | web | Generate recommended TLS configurations for many servers. | Details → |
| Let's Debug | free | web | Diagnose why Let's Encrypt certificate issuance fails for a domain. | Details → |
| Trivy | free | cli | All-in-one open-source vulnerability and misconfiguration scanner. | Details → |
| Gitleaks | free | cli | Detect and prevent hardcoded secrets in Git repositories. | Details → |
| TruffleHog | freemium | cli | Open-source tool to find, verify and monitor leaked credentials. | Details → |
| Bitwarden | freemium | web, desktop | Open-source password manager with a free generator and vault. | Details → |
| HTTP Observatory | free | web | Mozilla's scanner that grades a site's security headers and config. | Details → |
| Nmap | free | cli | The canonical network scanner for auditing your own hosts and services. | Details → |
| Wireshark | free | desktop | The world's foremost network protocol analyzer. | Details → |
Showing top 10 of 15. Browse the full grid below.
Reference & Standards · Security
Open-source web app security scanner for finding vulnerabilities in your own apps.
SSL & TLS · Security
Generate recommended TLS configurations for many servers.
SSL & TLS · Security
Diagnose why Let's Encrypt certificate issuance fails for a domain.
Dependency Security · Security
All-in-one open-source vulnerability and misconfiguration scanner.
Secret Scanning · Security
Detect and prevent hardcoded secrets in Git repositories.
Secret Scanning · Security
Open-source tool to find, verify and monitor leaked credentials.
Passwords & IDs · Security
Open-source password manager with a free generator and vault.
Headers & CSP · Security
Mozilla's scanner that grades a site's security headers and config.
Reference & Standards · Security
The canonical network scanner for auditing your own hosts and services.
Reference & Standards · Security
The world's foremost network protocol analyzer.
Dependency Security · Security
Fast static analysis for finding bugs and vulnerabilities in code.
Passwords & IDs · Security
Manage secrets, certificates and encryption centrally.
Penetration Testing · Security
Open-source penetration testing tool that automates SQL injection detection and exploitation.
Penetration Testing · Security
The most widely used penetration testing framework: exploit modules, payloads and post-exploitation.
Penetration Testing · Security
Debian-based Linux distribution shipping 600+ preinstalled penetration testing and forensics tools.