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.
Byte Counter (UTF-8) and Character Counter
Count UTF-8 bytes, Unicode code points, visible characters, and JavaScript string length for any text, with options for line endings, a BOM, and whitespace.
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 & Days Since Birth Calculator
Calculate age, days since birth, the next birthday, and days remaining from a birth date and reference date.
Days Between Dates Calculator
Enter a start date and an end date to get the date difference and the inclusive count that includes the start date. Year boundaries and leap years follow the calendar, and business days are handled by the business day calculator.
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: Rate, Savings & Stacked Coupons
Calculate a final price, find the discount rate and savings from sale prices, or apply stacked percent discounts and coupons in order.
Unit Price Comparator: Price per 100 g, 100 mL, or Piece
Compare two or three products by price per 100 g, per 100 mL, or per piece, and add shipping and coupons to compare the effective price.
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 Meters & Tatami to m² Converter
Convert between tsubo, square meters (m²), and tatami mats. Check tsubo to sqm, tatami to m2, and Japanese tatami size standards.
Tsubo to Square Meters & Tatami to m² Reference Table
Quickly look up tsubo to square meters and tatami to m² for Japanese room, land, and shop sizes.
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.
Web Metronome
A free metronome that runs in your browser. Adjust tempo and beats easily, and start practising at the tempo you measured with the BPM Tap Counter.
BPM Tap Counter
Measure the tempo (BPM) of a song from the intervals of your taps or clicks, then carry that tempo straight over to the Web Metronome to practise.
Tempo Converter (BPM to Seconds and Milliseconds)
Convert BPM into the length of one beat in seconds and milliseconds, the length of one bar, and the total time for a number of bars, plus every note value from whole notes to 32nd notes with dotted and triplet variants.