dev
Fast, privacy-friendly developer & text utilities. Everything runs in your browser — nothing is sent to a server.
Encoding & format
Base64
Encode/decode text and binary to Base64 (URL-safe variant included).
URL encoder
Encode/decode percent-escaped strings + parse URLs into components.
JSON formatter
Pretty-print, minify, validate, and inspect JSON with error highlighting.
Timestamp converter
Unix ↔ ISO 8601 ↔ human time, with millisecond precision and time-zone display.
Crypto & auth
Hash generator
MD5, SHA-1, SHA-256, SHA-384, SHA-512 — all computed in-browser via Web Crypto.
JWT decoder
Decode header + payload + signature; optional HMAC signature verification.
Text & data
Case converter
UPPER, lower, Title, camelCase, snake_case, kebab-case, CONSTANT_CASE, and more.
Regex tester
Live match highlighting, capture-group display, flag toggles, cheat sheet.
Diff viewer
Paste two texts; see line-level diff with additions, deletions, and unchanged context.
Visual & misc
Color converter
HEX ↔ RGB ↔ HSL ↔ CMYK + WCAG contrast checker.
QR generator
Convert any text or URL to a QR code; download as PNG or SVG.
Every tool here runs entirely client-side. No data is sent to any server beyond standard analytics. Inputs sync to the URL when relevant, so you can share specific operations.
Part of extrautil — a collection of free, practical tools.