All tools

Calculate body mass index with indicative adult category classification.

Interactive calendar with holidays of the world, lunar phases, memorable events. Displays holidays on the calendar.

Convert between currencies available in the downloaded exchange-rate dataset.

Calculate the exact difference between two calendar dates in days, weeks, and hours.

Convert between metres, centimetres, kilometres, yards, feet, and inches.

Online MP3 metadata editor. Edit title, artist, album, cover art, lyrics and other tags. Batch editing of multiple files.

Password generator using cryptographically secure randomness in modern browsers. Customize length, quantity, and character groups.

Calculate a percentage of a number, one number as a percentage of another, and percentage change.

Powerful random number generator: integer/fractional values, customizable ranges. Features: exclude duplicates, sort.

Solve a Boolean function from a formula, value vector, or editable truth table with every transformation shown.

Count words, letters, characters, and sentences in text. Works with Unicode alphabets.

A tool for memorizing poems and texts. Gradual word hiding for memory training.

Convert durations between units from nanoseconds to millennia.

Build Euler–Venn diagrams for 2–4 sets using formulas or actual elements, with membership tables and export.

Convert between kilograms, grams, tonnes, ounces, and pounds.