About us

Hakaroo is a growing collection of small, fast tools that run right in your browser: tests of your reflexes and senses, sound tools, measuring tools and more. There's nothing to install and no account to create.

The name comes from hakaru, the Japanese word for “to measure”. That's what most of our tools do: they measure something about you, your device or the world around you — and they try to do it honestly.

How we build every tool

• We start with what people need. We study what people actually search for in each language and try every popular alternative before writing a line of code.
• We aim to be the most accurate. We use the best measuring methods available in browsers, test them, and explain their limits on the page — including how your device affects the result.
• We show our sources. Facts and averages link to the research or official source they come from.
• Your data stays on your device. Tools run in your browser. Microphone or sensor data is never recorded or uploaded; saved results stay in your own browser.
• Fast on any phone. Pages are tiny and load in about a second, even on slow connections.
• Written for each language. Translations are written from scratch using the words and conventions people use locally, not machine-translated.

Found a mistake, or have an idea for a tool? We read every message: [email protected]