hexnook /dev/tools
Fast, free developer tools that run entirely in your browser. No sign-up, no uploads, no waiting on a server — just paste and go.
100% client-side
Nothing you paste is ever uploaded
No sign-up
Every tool works instantly
Unlimited & free
No limits, no watermarks
Open source engines
Web Crypto, native RegExp, JSON.parse
Every tool, right here
No tab-switching between five different sites. Pick one below.
JSON Formatter & Validator
Format, minify, and validate JSON instantly
Open toolBase64 Encode & Decode
Encode or decode text and files as Base64
Open toolHash Generator
Generate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes
Open toolRegex Tester
Test regular expressions with live match highlighting
Open toolJWT Decoder
Decode and verify JSON Web Tokens
Open toolColor Converter & Contrast Checker
Convert HEX, RGB, and HSL — check WCAG contrast
Open toolUUID / GUID Generator
Generate RFC 4122 v4 UUIDs instantly
Open toolPassword Generator
Generate strong, random passwords
Open toolUnix Timestamp Converter
Convert Unix time to and from human-readable dates
Open toolText Diff Checker
Compare two blocks of text line by line
Open toolWhy hexnook
Most "online tool" sites quietly upload whatever you paste to a server to process it. hexnook doesn't — every tool here runs on JavaScript already built into your browser (JSON.parse, the Web Crypto API, native RegExp), so your data never leaves the tab it's in.
That also means there's nothing to wait on. No request round-trip, no rate limit, no "processing…" spinner.