All tools
Browse fast, browser-based tools by category. Your input is processed locally in your browser.
Text
Tools for counting, cleaning, and normalizing writing, lists, form input, and text copied from spreadsheets or CSV data.
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 for Text and Katakana
Convert letters, numbers, symbols, spaces, and Japanese katakana between full-width and half-width forms, including zenkaku and hankaku text.
Duplicate Line Remover
Remove duplicate lines from multiline text while preserving the original order, with options for blank lines and surrounding spaces.
Whitespace / Space Remover
Clean up text by removing spaces, tabs, extra whitespace, and empty lines directly in your browser.
Date and time
Tools for date calculation, day counts, age checks from a birth date, and Japanese era names.
Japanese Year / Date Era Converter
Convert Gregorian years and dates into Japanese era notation from Meiji onward, including Reiwa, Heisei, Showa, and exact era transition dates.
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 days since birth, the next birthday, and days remaining.
Days Calculator
Calculate the number of days between two dates, including absolute and inclusive day counts.
Business Day Calculator (Excl. Weekends/Holidays)
Calculate an estimated date "N business days" in the future or past from a specific start date, excluding weekends and Japanese public holidays.
Developer and data
Utilities for JSON, URLs, Base64, UUIDs, HTML escaping, password generation, and quick data checks during development.
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.
Password / Random String Generator
Instantly generate strong, secure passwords or random strings directly in your browser. Customize the length and character types as needed.
HTML Entity Encoder / Decoder
Easily encode special characters into HTML entities to safely display code snippets, or decode HTML entities back to their original characters.
Lottery and decisions
Tools for choosing from candidates, drawing lots, deciding order, and making balanced teams locally in the browser.
Everyday
Tools for everyday calculations such as bill splitting, tax, discounts, BMI, wages, packing lists, cooking measures, and room area.
Split Bill Calculator
Split a total amount by the number of people and round each share by 1, 10, or 100 yen.
Japan Consumption Tax Calculator (8% / 10%)
Calculate Japanese consumption tax, before-tax prices, after-tax prices, and tax amounts for Japan tax rates of 8% and 10%.
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.
Tsubo to Square Meter / Tatami Area Converter
Convert between square meters (m²), tsubo, and tatami mats. Check tsubo to sqm, sqm to tsubo, and how many square meters 6 tatami is for Japanese real estate sizes.
Tsubo / Tatami Area Reference Table
A quick reference table for tatami mats, square meters (m²), and tsubo. Use it to scan common Japanese room and land sizes at a glance.
Hourly Wage Converter
Convert between hourly wage, monthly salary, and yearly salary estimates using work hours and working days.
Music and audio
Tools for tempo checks, rhythm practice, BPM measurement, and simple audio-assisted music practice.