Network & Web Security
Subnet, CORS, and CSP tools for configuring and reasoning about network and web security.
- Content Security Policy (CSP) BuilderAssemble a CSP header from common directives, with antipattern warnings.
- CORS Header GeneratorBuild Access-Control-* headers plus ready-to-paste Nginx/Apache/Express/ASP.NET snippets.
- IPv4 Subnet / CIDR CalculatorGet subnet mask, network, broadcast, and usable host range from an IP and prefix.
- Subnet / CIDR Range Expander & AggregatorList every IP in a range, or merge multiple ranges into minimal CIDR blocks.