Utilities

Predict the Lewis dot structure, valence electrons, central atom, lone pairs, and VSEPR geometry (linear / trigonal / tetrahedral / …) of a covalent molecule.

Health

Estimate your lean body mass (LBM) from sex, age, weight and height using three clinical formulas side by side, with derived body-fat percentage.

Generator

Generate a self-contained, dependency-free HTML countdown banner for any page. Target date, timezone, theme, one-shot or weekly-recurring mode, live in-browser rendering.

Health

Convert a daily calorie target into grams of carbohydrate, protein and fat. Pick a preset split — balanced (50/30/20), low-carb (35/40/25), keto (10/20/70) or high-protein (40/35/25) — or define your own percentages.

Games

The classic Magic 8 Ball. Ask any yes-or-no question, shake, and get one of 20 traditional answers (yes / no / uncertain). Classic English phrases or localized translations.

Games

Classic Mastermind code-breaking game. The computer picks a secret color code; you guess row by row. Black pegs = right color and position; white pegs = right color, wrong position.

Text Processing

Decode leetspeak (1337) to plain text and score how plausibly leet an input is — for password-policy bypass screening, profanity-filter evasion, and log-noise filtering.

Astronomy

Convert between light-years (ly), parsecs (pc), astronomical units (AU), kilometers and meters using IAU-defined constants, with a parallax-angle → distance helper.

Math & Numbers

Compute kinetic energy, mass, or velocity from the other two, with momentum and km/h conversion

Math & Numbers

Compute the current-limiting resistor for LEDs in series with power, nearest standard value and wattage rating

Text Processing

Convert text to and from leet speak (1337). Encode with Basic, Full, or Caps styles, or decode leet back to plain text.

Text Processing

Convert text line endings between LF (Unix/macOS), CRLF (Windows), and CR (classic Mac). Normalizes mixed endings in one pass and reports the original breakdown.