Keyboard & Mouse Checker

What does this tool do

The Keyboard & Mouse Checker lets you test your keyboard and mouse input in real time. It displays key codes, mouse position, button clicks, scroll delta, and modifier keys. Everything runs in your browser. No data is sent to any server. Useful for verifying hardware, debugging input issues, and checking key codes for development.

How to use it

1. Keyboard — Click the keyboard area (or tab to it) and press any key. Events appear in the table with key, code, keyCode, repeat status, and modifiers.
2. Mouse — Move and click in the mouse test zone. Position updates live; clicks and scroll events are logged.
3. Clear — Use Clear on each section to reset the event list.
4. Right-click — Right-click in the mouse zone to test the right button (the browser context menu is suppressed there).

How it works

• Keyboard — Listens to keydown events on a focusable area. Displays key (character), code (physical key), keyCode (legacy), repeat (key held), and modifier flags (Alt, Ctrl, Shift, Meta).
• Mouse — Listens to mousemove, mousedown, mouseup, and wheel in a dedicated zone. Shows cursor position (x, y), button (Left, Middle, Right), scroll delta (X, Y), and modifiers.
• Events are stored in memory with a maximum limit (20 keyboard, 15 mouse, 10 wheel) to avoid unbounded growth.
• All processing runs entirely in your browser. No data is sent to any server.

Use cases & examples

• Hardware check — Verify that all keys and mouse buttons work after replacing a keyboard or mouse.
• Key code lookup — See the exact key, code, and keyCode for any key (useful for developers).
• Modifier testing — Confirm Shift, Ctrl, Alt, and Meta are detected correctly.
• Scroll wheel — Test scroll direction and delta in the mouse zone.

Example

• Press A → key: "a", code: "KeyA", keyCode: 65
• Press Shift+A → modifiers: "Shift", key: "A"
• Left-click at (320, 150) → down Left @ (320, 150)
• Scroll down → delta Y: -100

Limitations & known constraints

• Browser only — Events are limited to what the browser exposes. Some low-level hardware behavior is not visible.
• Focus required — Keyboard events are captured only when the keyboard area has focus. Click or tab into it first.
• Mouse zone only — Mouse events are captured only within the dedicated test zone, not elsewhere on the page.
• No keylog persistence — Events are kept in memory only; they are lost on page refresh. Nothing is stored or sent to a server.