Browser-based web tools
Karu Tools
Karu Tools is a free collection of browser-based utilities for everyday tasks — counting characters, calculating ages, splitting bills, and more. No sign-up required.
Recommended tools
All tools Character Counter Edit text while counting characters, characters without whitespace, lines, paragraphs, and manuscript-page estimates directly in your browser, then copy the result. 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. Age Calculator Calculate age from a birth date and reference date, including days since birth, the next birthday, and days remaining. Split Bill Calculator Split a total amount by the number of people and round each share by 1, 10, or 100 yen.