Keyboard Tester

A web tool for verifying keyboard functionality in real time: which keys are detected, how many simultaneous presses register, and whether ghosting issues exist.

Demo: keyboardtester.pablocostas.dev | Code: GitHub

What it does

Keyboard Tester captures keydown and keyup events to display an interactive visual representation of the keyboard. Pressed keys are highlighted on a layout-specific grid, with support for ES, ANSI, and ISO layouts. A keystroke counter tracks total presses and simultaneous key combinations, including modifier keys.

The tool also detects key repeat frequency and displays Caps Lock, Num Lock, and Scroll Lock status. A fullscreen mode and quick reset button make it convenient for testing after cleaning or repairing a keyboard.

Tech stack

• Frontend: Next.js, React, TypeScript, TailwindCSS
• Input: Native keyboard events (keydown/keyup) with state management and prevention handling

Key features

• Live key press detection with layout-specific highlighting (ES, ANSI, ISO)
• Keystroke counter and simultaneous key combination detection
• Key repeat rate indicator and lock key status display (Caps, Num, Scroll)
• Fullscreen mode and quick reset for convenient testing