DevTools
Subnet calculation, DNS lookup, IP conversion, SSL certificate checks, and more — the networking utilities developers reach for, in one place. Most run in the browser; some use a server API.
IP / Subnet
Subnet Calculator
Compute network/broadcast/host range and mask from an IPv4 CIDR.
CIDR ↔ Range
Convert between CIDR and IP ranges and count the addresses covered.
IP Base Converter
Convert IPv4 between decimal integer, hex, and binary.
IPv6 Compress/Expand
Compress (::) or expand IPv6 addresses and validate them.
MAC Address Tool
Reformat and validate MAC addresses; analyze local/unicast bits.
DNS / Network
Web / Security
Encoding / Convert
Base64 Encoder
Encode/decode text to and from Base64 (UTF-8 supported).
URL Encoder
URL-encode and decode strings.
JWT Decoder
Decode a JWT's header and payload and check its expiry.
Timestamp Converter
Convert between Unix timestamps and dates, both ways. Supports timezones and ms/s units.
JSON Formatter
Pretty-print or minify JSON and validate it, with error location.
Hash Generator
Generate SHA-1/256/384/512 hashes of text (Web Crypto).
Regex Tester
Test regular expressions and highlight matches and capture groups.
Regex Snippets
Search and copy common regex patterns — email, URL, date, and more.
Cron Parser
Explain a cron expression in plain English and show the next run times.