unitconversions.app is a free online unit conversion tool that lets you instantly convert between hundreds of units across 14 categories: length, weight/mass, temperature, volume, area, speed, time, digital storage, pressure, energy, frequency, angle, fuel economy, and cooking.
All conversions run entirely in your browser using pure JavaScript math with hardcoded, internationally accepted conversion factors. No data is ever sent to a server. You can verify this by opening your browser's Network tab — you will see zero outbound requests when you perform a unit conversion.
We use officially defined conversion factors wherever possible. For example, 1 inch is defined as exactly 2.54 centimeters by international agreement since 1959. Results are displayed to up to 6 significant figures, which is more than sufficient for everyday use.
We take your privacy seriously. Since all conversions happen client-side, your values never leave your device. We use Google AdSense for advertising, which may use cookies. See our Privacy Policy for details.