Useful Network Tools starting points

Jump into a common task, then use the full directory below for more specialized tools.

IP Range to CIDR Converter IP Range Calculator Wildcard Mask Calculator CIDR to IP Range Converter IP Address to Binary Converter VLSM Calculator

24 network tools

Network Tools

Free subnet, CIDR, VLSM, IPv4/IPv6 conversion, route aggregation, DNS and public-IP tools with browser-local address math.

Calculate → allocate → summarize → verify

Use deterministic local IP math for address planning. Only DNS and public-IP discovery call external services, and those pages label that boundary clearly.

Subnet a single network

Calculate one network, convert masks, inspect wildcard/binary values, or split equal child blocks.

Subnet CalculatorInspect network, broadcast, first/last usable host, mask, wildcard, address class/type, binary octets, and child-subnet allocation locally.CIDR CalculatorEnter IPv4 CIDR notation for deterministic browser-local subnet math and copyable results.Subnet Mask CalculatorTranslate /prefix and dotted-decimal subnet masks in either direction and reject non-contiguous mask bits.Wildcard Mask CalculatorCalculate inverse masks, matching prefixes, and address counts locally for ACL planning.Subnet SplitterChoose a longer target prefix to page through child networks, usable host ranges, broadcast addresses, and per-subnet capacity entirely in your browser.CIDR Cheat SheetUse a complete subnet reference table with copy and CSV export for study or network planning.

Plan address space

Allocate different host requirements with VLSM or aggregate existing routes into exact/minimal summaries.

VLSM CalculatorEnter a parent network plus named host counts to allocate largest-first VLSM subnets with network, host range, broadcast, capacity, waste, copy, and CSV output.Supernet CalculatorPaste IPv4 addresses or networks to compare exact CIDR aggregation with the smallest one-route covering supernet and its extra address space.IP Range CalculatorInspect range size, endpoints, and exact CIDR coverage without sending address data to a server.IP Range to CIDR ConverterSummarize a contiguous IPv4 range without over-covering addresses outside the requested interval.CIDR to IP Range ConverterNormalize a CIDR block and expose its exact address interval locally.

IPv6 & address inspection

Normalize, validate, classify, compress, expand, and subnet IPv6 alongside IPv4 validation/conversion.

IPv6 Subnet CalculatorInspect a supplied IPv6 address and /0–/128 prefix locally without remote registry or routing claims.IPv6 Address ValidatorCheck IPv6 syntax locally and view compressed, fully expanded, address type, and 128-bit hexadecimal forms.IPv6 Address CompressorEnter expanded or partially compressed IPv6 and get the shortest normalized representation plus the full expanded form.IPv6 Address ExpanderNormalize IPv6 input into a full 128-bit expanded address while also showing the canonical compressed form.IPv4 Address ValidatorCheck IPv4 syntax, numeric range, class, public/private/special classification, binary form, and decimal value.IP Address Type CheckerPaste an IPv4 or IPv6 address to inspect common standards-based address classifications without a remote lookup.

Live network lookups

Use live external services only where browser-local math cannot answer the question.

What Is My IP Address?View a public IPv4/IPv6 address when the external endpoint is reachable, copy it, and inspect browser/network context without pretending to identify a device or exact location.DNS LookupLook up A, AAAA, MX, TXT, NS, CNAME, SOA, CAA, PTR, or a common-record bundle; results depend on the live DNS resolver and network.

Learn & verify

Practice subnet boundaries, then use the calculator or cheat sheet to verify the result.

Subnetting Practice QuizDrill CIDR subnet math locally with difficulty controls, instant explanations, score, streak, and saved best streak—no account required.CIDR Cheat SheetUse a complete subnet reference table with copy and CSV export for study or network planning.Subnet CalculatorInspect network, broadcast, first/last usable host, mask, wildcard, address class/type, binary octets, and child-subnet allocation locally.

All Network Tools

Subnet Calculator

Calculate IPv4 subnet boundaries with CIDR/mask input, binary detail, wildcard mask, host capacity, and equal-size split planning.

What Is My IP Address?

Check the public IP address returned by an external echo service, then classify the address locally.

DNS Lookup

Query common public DNS record types through DNS-over-HTTPS with TTL and resolver-status context.

CIDR Calculator

Calculate an IPv4 CIDR network, broadcast, usable range, mask, wildcard, total addresses, and optional child prefixes.

Subnet Mask Calculator

Convert IPv4 CIDR prefixes and contiguous dotted masks with wildcard, binary, address-count, and example-network context.

Wildcard Mask Calculator

Convert CIDR/subnet masks to Cisco-style IPv4 wildcard masks and reverse-check contiguous wildcard values.

IP Range Calculator

Measure an IPv4 start/end interval and summarize it as the smallest exact list of CIDR blocks.

CIDR to IP Range Converter

Convert IPv4 CIDR notation into network, broadcast, total addresses, and usable host boundaries.

IP Range to CIDR Converter

Convert an arbitrary IPv4 start/end interval into the minimal exact CIDR block list.

IP Address to Binary Converter

Convert an IPv4 address to a 32-bit binary representation.

Binary to IP Address Converter

Convert 32 binary bits to a dotted-decimal IPv4 address.

IP Address to Decimal Converter

Convert an IPv4 address to its unsigned 32-bit decimal integer.

Decimal to IP Address Converter

Convert an unsigned 32-bit decimal integer to IPv4 notation.

IPv4 Address Validator

Validate IPv4 dotted-decimal addresses and inspect their address type.

IPv6 Address Validator

Validate IPv6 addresses and normalize compressed and expanded forms.

IPv6 Address Compressor

Compress a full IPv6 address using standard zero suppression and :: notation.

IPv6 Address Expander

Expand a compressed IPv6 address to eight four-digit hexadecimal hextets.

IPv6 Subnet Calculator

Calculate IPv6 subnet network/final addresses, normalized forms, prefix length, and total address count.

IP Address Type Checker

Classify IPv4 and IPv6 addresses as private, public, loopback, link-local, multicast, documentation, or other special ranges.

CIDR Cheat Sheet

Browse and filter all IPv4 /0–/32 masks, wildcards, address counts, and modern/classic usable-host conventions.

VLSM Calculator

Design variable-length IPv4 subnets from one parent CIDR and multiple host requirements.

Subnet Splitter

Split one IPv4 CIDR block into equal-size child subnets and inspect each boundary.

Supernet Calculator

Aggregate IPv4 addresses and CIDR blocks into minimal exact routes and a single covering supernet.

Subnetting Practice Quiz

Practice IPv4 subnetting with generated network, broadcast, mask, and usable-host questions.