Network
IP Subnet Calculator
Calculate network address, broadcast, host range and masks from an IPv4 address and CIDR prefix.
CIDR Calculator
Convert a CIDR block to its IP range and total addresses, or find the smallest CIDR covering a range.
Subnet Mask Converter
Convert between dotted subnet mask, CIDR prefix length and wildcard mask.
IP Range Calculator
Get the total address count and the list of CIDR blocks that exactly cover a start-to-end IP range.
IPv4 to IPv6 Converter
Convert an IPv4 address to its IPv4-mapped IPv6 forms, full notation and 6to4 prefix.
IPv6 Expander & Compressor
Expand a compressed IPv6 address to full form and compress a full one back down.
MAC Address Formatter
Normalize a MAC address into colon, hyphen and Cisco dot notations in upper and lower case.
Binary IP Converter
Convert an IPv4 address to dotted binary, a 32-bit decimal integer and hexadecimal.
Port Number Lookup
Searchable reference of common TCP and UDP port numbers and their services.
DNS Record Types Reference
Searchable reference of DNS record types and what each one does.
IP Class Identifier
Identify an IPv4 address class (A-E) and whether it is private, public, loopback or reserved.
HTTP Header Reference
Searchable reference of common HTTP request and response headers.
User-Agent Parser
Paste a User-Agent string to detect the browser, operating system and device type.