Networking Tools
IP/CIDR, DNS, ports, MIME, user-agent, HTTP headers.
28 tools · all run in your browser
IP Address Lookup
Parse and validate IPv4/IPv6 addresses and CIDR ranges
HTTP Status Reference
Quick lookup of HTTP status codes and their meanings
DNS Record Explainer
Explain A, AAAA, CNAME, MX, TXT, SRV and other DNS records
WebSocket Frame Decoder
Decode WebSocket frame headers and payloads from hex
Port Reference Lookup
Look up common services for any TCP/UDP port number
MIME Type Lookup
Convert between file extensions and MIME types
Certificate Decoder
Decode X.509 PEM certificates into readable fields
HPKP Generator
Generate HTTP Public Key Pinning headers from a certificate
User-Agent Parser
Parse browser, OS, device from a User-Agent string
CORS Header Tester
Analyze CORS response headers for misconfigurations and security issues
CIDR Calculator
Calculate network address, broadcast, host range from CIDR notation
HTTP Header Analyzer
Analyze HTTP headers for security, caching, and best practices
MAC Address Lookup (OUI)
Identify the manufacturer from a MAC address OUI prefix
HTTP Method Reference
Quick reference for all HTTP methods with use cases and safety info
Query String Builder
Build ?k=v&k=v strings from key=value lines — repeating keys OK
Basic Auth Generator
Base64-encode user:pass into an HTTP Basic Authorization header
Bearer Token Builder
Wrap a raw token in HTTP Authorization + curl + fetch snippets
HTTP Header Builder
Compose request headers — output as curl flags and fetch options
Subnet Calculator (v2)
CIDR → subnet mask, network, broadcast, first/last host, host count
IPv6 Expander
Expand ::abbreviated IPv6 and also emit the canonical compressed form
IPv4 → IPv6 Mapper
IPv4-mapped IPv6 address (::ffff:a.b.c.d) — RFC 4291 representation
RFC Lookup
Search 25+ foundational RFCs by number, title, or topic
Well-Known Ports
40+ standard TCP/UDP ports — search by number, service, or keyword
DNS Lookup
DNS resolution and record lookup
WHOIS Lookup
WHOIS domain lookup
IP Geolocation
GeoIP lookup with ISP info
Network Calculator
CIDR subnet calculator with utilities
Port Scanner
Port status checker with service identification