All tools
Browse fast, browser-based tools by category. Your input is processed locally in your browser.
Text
Tools for working with writing, strings, and input text.
Character Counter
Edit text while counting characters, characters without whitespace, lines, paragraphs, and manuscript-page estimates directly in your browser, then copy the result.
Full-width / Half-width Converter
Convert ASCII letters, numbers, symbols, and spaces between full-width and half-width forms.
Duplicate Line Remover
Remove duplicate lines from multiline text while preserving the original order, with options for blank lines and surrounding spaces.
Whitespace Remover
Clean up text by removing extra whitespace (spaces, tabs) and empty lines.
Date and time
Tools for checking dates, differences, and Japanese era names.
Japanese Era Converter
Convert Gregorian dates from the Meiji era onward into Japanese era notation with era boundary dates handled correctly.
Japanese Era Table
Check a year-by-year table of Gregorian years, Japanese era names, zodiac animals, and sexagenary cycle labels.
Age Calculator
Calculate age from a birth date and reference date, including the next birthday and days remaining.
Days Calculator
Calculate the number of days between two dates, including absolute and inclusive day counts.
Developer and data
Utilities for development, data formatting, and identifiers.
URL Encoder / Decoder
Encode text for URLs and decode percent-encoded strings locally in your browser.
Base64 Encoder / Decoder
Encode text to Base64 and decode Base64 strings back into UTF-8 text locally in your browser.
JSON Formatter / Minifier
Format and minify JSON in your browser, with parse errors shown when the input is invalid.
UUID Generator
Generate UUID v4, v5, and v7 values in your browser.
Lottery and decisions
Tools for random picks, drawing lots, and lightweight decisions.
Everyday
Tools for everyday preparation, shopping, and quick calculations.
Split Bill Calculator
Split a total amount by the number of people and round each share by 1, 10, or 100 yen.
Tax Calculator
Calculate Japanese before-tax, after-tax, and consumption tax amounts for 8% and 10% rates.
BMI Calculator
Calculate your BMI (Body Mass Index) and ideal weight from your height and weight, and see your weight category.
Discount Calculator
Calculate the final price and your savings from the original price and discount rate (%) or amount.
Packing Checklist Maker
Create a starter packing checklist for travel, business trips, hospital stays, or going out with kids, then add items and copy the list.
Cooking Measure Converter
Convert between tablespoons, teaspoons, cups, and grams for common ingredients like water, sugar, salt, and soy sauce.
Area Converter (Square meters, Tsubo, Jyo)
Instantly convert between square meters (m²), tsubo, and jyo (tatami mats). You can also choose tatami size standards like Chukyo-ma and Edo-ma.
Area Quick Reference Table
A quick reference table for jyo (tatami mats), square meters (m²), and tsubo. Perfect for checking room sizes when apartment hunting.
Music and audio
Tools for music practice and audio processing.