# About ControllerTests

> Why ControllerTests exists, how each controller, keyboard, mouse and screen test measures your hardware, and what we do (and never do) with your data.

Canonical page: https://controllertests.com/about/

A free, independent testing lab for the hardware you touch every day — built to give precise answers in plain language.

## What ControllerTests is

ControllerTests started with one question every gamer eventually asks — “is my controller broken, or is it the game?” — and grew into a set of free tools that check whether your controller, keyboard, mouse, screen and speakers work the way they should. Each tool reads the raw data your browser already receives from the device, measures it, and tells you what the result means — for example whether a thumbstick drifts, whether a key registers twice, or whether a mouse button double-clicks on its own.

## How the tests measure

- **Controllers** are read through the W3C [Gamepad API](https://www.w3.org/TR/gamepad/): every button value and stick axis, sampled every display frame.
- **Keyboards** use the physical `KeyboardEvent.code` of each key and high-resolution event timestamps, so layout and language settings don't matter.
- **Mice** use Pointer Events, including coalesced and raw updates where the browser supports them, to count reports per second and the time between clicks.
- **Reaction and click tests** use the browser's high-resolution clock (`performance.now()`) and align the stimulus with the screen's refresh.

Every page has a “method and limits” section that explains exactly what is measured, the thresholds we use, and what a browser cannot see.

## Privacy

Tests run locally. Your inputs, results and audio are processed on your device and are not uploaded. Best scores and your theme choice are kept in your browser's local storage so you can clear them at any time. Read the [privacy policy](https://controllertests.com/privacy/) for details.

## Independence

ControllerTests is not affiliated with Sony, Microsoft, Nintendo or any hardware maker. Product names are used only to describe compatibility.

_Last updated: 2026-10-01_