Tools
Developer utilities & practical tools. No signup, no tracking — everything runs in your browser.
Developer Tools
JSON Formatter
Format, validate, and minify JSON data.
Base64 Encoder / Decoder
Encode and decode Base64 strings with full UTF-8 support.
URL Encoder / Decoder
Percent-encode and decode URLs with encodeURIComponent or encodeURI.
UUID Generator
Generate random UUID v4 values with the Web Crypto API.
Hash Generator
Compute SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text.
Regex Tester
Test and debug regular expressions with live match highlighting.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates.
Color Converter
Convert colors between HEX, RGB, and HSL with a live preview.
JWT Decoder
Decode and inspect JSON Web Tokens in your browser.
Diff Viewer
Compare two texts line by line.
HTML Entities
Encode and decode HTML entities.
Lorem Ipsum
Generate placeholder text by paragraphs, sentences, or words.
Number Base
Convert between binary, octal, decimal, and hex.
Text Counter
Count characters, words, sentences, and analyze text frequency in real time.
Markdown Preview
Render Markdown to HTML live as you type.
QR Code Generator
Turn any text or URL into a QR code and download it as PNG or SVG.
Life in Japan
Payslip Decoder
Understand each line of a Japanese payslip and your take-home pay.
Tax Simulator
Estimate Japanese income tax, resident tax, and take-home pay.
Visa Renewal Timeline
See when to renew your residence status and what documents you need.
Moving Checklist
Track every procedure for moving house in Japan on a timeline.
Korean ⇄ English Typing
Recover text typed in the wrong keyboard mode.