TOOL15 records
Network & Developer Tools
Free utilities that run in your browser: subnet and CIDR calculators, port lookup, IP tools, encoders, converters, hash and UUID generators, chmod calculator.
Every tool here runs in your browser. Except DNS Lookup, which must query a resolver, nothing you type is sent anywhere. Each tool sits next to the reference records that explain the concept behind it.
Networking
Subnets, CIDR, ports, IP addresses and DNS.
- CIDR CalculatorConvert a CIDR block to its address range and host count, convert an address range to the minimal covering…
- DNS LookupLook up DNS records (A, AAAA, MX, TXT, NS, CNAME, SOA, PTR) for any domain from your browser, using…
- IP Address ConverterConvert an IPv4 address between dotted-decimal, 32-bit integer, hexadecimal and binary forms. Runs entirely…
- Port LookupLook up any TCP or UDP port by number or service name against the IANA registry, with links to…
- Private IP CheckerCheck whether an IPv4 or IPv6 address is private (RFC 1918), public, carrier-grade NAT, loopback, link-local…
- Subnet CalculatorFree IPv4 subnet calculator: enter an address and mask or prefix to get the network address, broadcast,…
Developer & system
Encoding, parsing, converting and generating.
- Base64 Encoder / DecoderEncode text to Base64 and decode Base64 to text, with UTF-8 support and URL-safe variant, entirely in your…
- chmod CalculatorConvert Unix file permissions between checkboxes, symbolic notation (rwxr-xr-x) and octal (755, 644), and…
- Number Base ConverterConvert a number between hexadecimal, decimal, binary and octal instantly in your browser. Handles large…
- Unix Timestamp ConverterConvert Unix epoch timestamps (seconds or milliseconds) to human-readable UTC and local dates, and convert a…
- URL Encoder / DecoderPercent-encode text for safe use in URLs and decode percent-encoded strings, with component and full-URI…
- URL ParserParse a URL into its scheme, host, port, path, query parameters and fragment, and decode the query string,…
- User-Agent ParserParse a User-Agent string to identify the browser, operating system, device type and rendering engine, in…
Hashing & identifiers
Hashes and unique identifiers.