Free Network Tools
54 fast, free, no-nonsense networking tools โ subnet math, IP & IPv6 converters, DNS and RDAP lookups, encoders, generators and references. Most run entirely in your browser; nothing is stored.
๐งฎ Subnetting & IP Math
๐งฎ Subnet Calculator
Network, broadcast, mask, wildcard, host range & host count from any IP/CIDR.
๐ CIDR โ IP Range
Turn 10.0.0.0/8 into its first IP, last IP and total address count.
๐ IP Range โ CIDR
Given a start and end IP, get the smallest set of CIDR blocks covering it.
๐ IP Address Sorter
Sort a messy list of IPv4 addresses numerically and de-duplicate them.
๐ญ Subnet Mask Converter
Convert between dotted mask, /CIDR prefix, and wildcard mask instantly.
๐ IP โ Binary
See any IPv4 address as 32 bits of binary, octet by octet.
๐ข IP โ Decimal
Turn 192.168.0.1 into its 32-bit integer, and integers back into IPs.
#๏ธโฃ IP โ Hex
Convert 192.168.0.1 to 0xC0A80001 and hex back to an IP.
๐งฉ VLSM Calculator
Carve a network into right-sized subnets from a list of host requirements.
๐ Hosts per Subnet
How many usable hosts are in a /24, /26, /30? Look up any prefix.
๐งท CIDR Aggregator
Merge and summarise a list of CIDRs into the fewest possible blocks.
๐ฏ IP-in-Subnet Checker
Is 10.0.5.7 inside 10.0.0.0/16? Check any IP against any CIDR.
๐ Wildcard Mask Calculator
Get the wildcard (inverse) mask for any subnet mask or CIDR prefix.
๐ฒ Random IP Generator
Generate random IPv4/IPv6 addresses for testing, with public-only option.
๐ IPv6 Tools
๐ฌ IPv6 Expand/Compress
Expand 2001:db8::1 to full form, or compress a long IPv6 to its shortest form.
๐งฎ IPv6 Subnet Calculator
Prefix, first/last address and subnet counts for any IPv6 CIDR.
๐ IPv6 โ Binary
See any IPv6 address as 128 bits of binary.
๐ IPv4 โ IPv6
Turn an IPv4 into its ::ffff: mapped, compatible and 6to4 IPv6 forms.
๐ IPv6 Reverse DNS
Build the ip6.arpa PTR name for any IPv6 address.
โฉ๏ธ IPv4 Reverse DNS
Build the in-addr.arpa PTR name for any IPv4 address.
๐งฌ EUI-64 Calculator
Turn a MAC address into a Modified EUI-64 IPv6 interface identifier.
๐ข Converters & Encoders
๐ข Base Converter
Convert numbers between binary, decimal, hex and octal instantly.
๐ ฑ๏ธ Base64 Encode/Decode
Encode text to Base64 and decode it back โ UTF-8 safe, in-browser.
๐ URL Encode/Decode
Percent-encode text for URLs or decode it back to plain text.
๐ Hex โ Text
Convert text to hex bytes and hex back to text.
0๏ธโฃ Text โ Binary
Convert text to 8-bit binary and binary back to readable text.
๐ค ASCII Table
A searchable ASCII table: decimal, hex, octal, binary and the character.
๐ท๏ธ MAC Address Formatter
Reformat a MAC between colon, hyphen, Cisco-dot and bare styles.
๐ JSON Formatter
Prettify, minify and validate JSON โ 100% in your browser.
๐ซ JWT Decoder
Decode a JWT's header and payload locally โ nothing is uploaded.
โฑ๏ธ Unix Timestamp Converter
Convert Unix epoch seconds/millis to human time (UTC & local) and back.
๐ Network Lookups
๐ What Is My IP
Your public IPv4/IPv6, location, ISP and browser โ looked up in your browser.
๐บ๏ธ IP Geolocation Lookup
Look up the approximate location, ISP and ASN of any public IP.
๐ DNS Lookup
Look up A, AAAA, MX, TXT, NS, CNAME and more for any domain.
๐ Reverse DNS Lookup
Find the hostname (PTR record) behind any IPv4 or IPv6 address.
๐ง MX Record Lookup
See which mail servers handle a domain's email, with priorities.
๐ TXT Record Lookup
Read a domain's TXT records, including SPF and verification strings.
๐ Domain RDAP Lookup
Modern WHOIS: registrar, statuses and nameservers for a domain via RDAP.
๐ข IP RDAP Lookup
Find the owning network, org and ASN for any IP via RDAP.
๐ญ MAC Vendor Lookup
Identify a device's manufacturer from its MAC address (OUI).
๐ก HTTP Ping Test
Measure round-trip latency to a URL from your browser (HTTP-based).
๐ Generators & Security
๐ Password Generator
Generate strong random passwords locally โ length and character sets your call.
๐ UUID Generator
Generate random v4 UUIDs โ one or a batch โ and copy them.
๐ Hash Generator
SHA-1/256/384/512 hashes of any text, computed locally.
๐ฐ Random MAC Generator
Generate random MAC addresses for testing, in your preferred format.
๐ช Random Port Generator
Generate random port numbers within well-known, registered or ephemeral ranges.
๐๏ธ Token Generator
Generate random hex, base64url or alphanumeric tokens locally.
โ๏ธ HMAC Generator
Compute HMAC-SHA256 (and more) of a message and key, locally.
๐ References & Cheat Sheets
๐ฆ Common Ports
A searchable list of common TCP/UDP ports and their services.
๐ฅ HTTP Status Codes
Every HTTP status code, its name and meaning โ searchable.
๐ Private IP Ranges
RFC 1918 private ranges and other special IP blocks, with a live checker.
๐๏ธ DNS Record Types
What A, AAAA, CNAME, MX, TXT, SRV, CAA and other DNS records do.
๐ Subnetting Cheat Sheet
Every CIDR /0โ/32 with mask, wildcard, block size and host count.
๐ถ IP Protocol Numbers
IANA IP protocol numbers: 1 ICMP, 6 TCP, 17 UDP, 47 GRE and more.