About this site

This site is a collection of free, single-purpose web tools. Each tool does one job well: calculators, text tools, and device tests such as a microphone tuner, a sound meter, a webcam test and a screen test.

How the tools work

Every tool runs in your browser. Calculations and processing happen on your own device, so you get results instantly and nothing you enter has to leave your computer or phone.

Each page also explains how its tool works, including the formulas or methods behind the result, so you can understand and check what you see.

How the site is funded

The tools are free to use. The site is paid for by advertising shown on its pages.

Accuracy and corrections

We review our content and fix mistakes when they are reported. If you spot a wrong result, an unclear explanation or a translation error, please let us know through the contact page.