2.5D Mechanical Keyboard Tester

This keyboard tester lights up and presses down the matching keycap on a 2.5D keyboard model whenever you press a key, and releases it when you let go. It is a quick way to check a new, used or laptop keyboard for dead keys, chattering or keys that stick. The model covers Esc, F1 to F12, the number row, the letter keys, modifiers such as Shift, Ctrl, Alt and Win, and the arrow keys, and it tells the left and right Shift apart. Detection is based on each key's physical position, so the right key lights up even with Shift held, a non-English input method active or a different keyboard layout.

Every keystroke plays a sound, and you can switch between Clicky Blue, Linear Red, Tactile Brown and a playful Alpa bleat. The sounds are synthesized live with the Web Audio API rather than recorded: Blue is a sharp, high click, Red a muted bottom-out thud and Brown sits in between. They give you a feel for how switch types differ, but they are not the sound of your own keyboard. Clicking a keycap on screen with the mouse also plays the sound and counts toward the stats.

The Typing Statistics panel shows Total Hits, Typing Speed (WPM) and your Most Active Key. WPM takes the keystrokes from the last five seconds, scales them to a minute and divides by five characters per word, so it reflects your current rhythm rather than a formal typing test score. It does not drop to zero when you stop; it updates on your next keystroke. When you hold a key down, the operating system's auto-repeat keeps the keycap lit but is not counted again.

A few things to keep in mind: the Fn key is usually handled inside the keyboard itself, so the browser never sees it and it will not light up. Win (Command on a Mac), Print Screen and some shortcuts may be captured by the operating system first. Keys that are not on the model, such as the numeric keypad, Delete or Home, do not react. Everything runs locally in your browser; nothing you type is stored or sent anywhere.