Networking

Complete reference for all HTTP status codes with descriptions and use cases.

Search and browse all MIME types and their associated file extensions.

Calculate IP ranges, subnet masks, and broadcast addresses from CIDR notation.

Validate IPv4 and IPv6 addresses and get detailed information.

Look up well-known TCP/UDP ports and their associated services.

View detailed browser, device, screen, and hardware information.

Calculate Unix file permissions with a visual toggle grid and symbolic/octal notation.

Generate CORS headers and config snippets for Express, Next.js, Vite, and Nginx.

Validate and reformat a MAC address between colon, hyphen, dot, and bare notation, decode its unicast/multicast and universal/local bits, or generate a random one.

Build SPF and DMARC DNS TXT record strings from simple form inputs, ready to paste into your DNS zone.

Expand shorthand IPv6 addresses with :: zero-compression to their full 8-group form, or compress a full address back to its shortest valid representation.

Convert a umask to default file and directory permissions (and back), with symbolic notation and common presets like 022, 027 and 077.