Everyday developer utilities in one clean place

Time Zone Converter

Swap between any two time zones instantly (default UTC and JST).

URL Encode / Decode

Encode or decode URLs without leaving your browser.

URL Params → JSON

Turn query strings into JSON objects for quick inspection.

JSON Formatter

Pretty-print or minify JSON for quick validation.

Base64 / 58 / 32

Switch tabs to encode or decode with any base in one place.

Regex Tester

Validate patterns, flags, and captured groups in one view.

Text & Code Suite

Count text, escape HTML/XML, minify CSS/JS, and generate passwords.

JWT Tool

Create and decode HS256-signed tokens in the browser.

UUID Generator

Generate UUIDv4 identifiers and copy instantly.

Diff Viewer

Visualize text changes with inline highlighting.

QR Generator

Turn any text or URL into a QR code and save as PNG.

QR Reader

Scan codes with the browser camera and decode locally.

日本語版

日本語UIで同じツールを利用できます。