---
title: "Keyboard test"
description: "Free online keyboard tester. Press each key and watch it light up to find dead keys, check modifiers and function keys. Works with any layout."
url: https://www.test-webcamp.com/keyboard-test.html
site: Webcamp
updated: 2026-08-28
---

# Keyboard test

_Press every key and watch it light up. Keys stay green once tested, so you can work across the whole board and see at a glance which ones never responded._

## How to use it

Click anywhere on the page first so it has keyboard focus, then work across the board pressing every key in turn. A key turns bright while held and stays green afterwards, so you can see your coverage building without watching the screen constantly.

The counter in the readout tracks how many distinct keys have responded. If you have pressed everything and the count is short, the keys still dark are the ones to investigate.

**This tests physical keys, not characters.** The board reads key codes, which describe position rather than the letter produced. On an AZERTY or Dvorak layout the key in the QWERTY "Q" position still reports as KeyQ. That is correct behaviour and is what makes the test layout-independent.

## What the results mean

| Result | Likely cause |
| --- | --- |
| One key never registers | Physical failure: debris, worn contact, or a dead switch |
| A whole row is dead | Ribbon cable or connector fault, common on laptops after a spill |
| Key registers twice per press | Switch chatter from a worn or dirty contact |
| Key registers but types nothing | Layout or input language setting, not hardware |
| Certain pairs will not register together | Key rollover limits, normal on membrane keyboards |

## Before you replace a keyboard

A single unresponsive key is often just debris. Turn the keyboard upside down and give it a firm shake, then use compressed air at an angle rather than straight down, which pushes dust further in. On a mechanical keyboard you can pull the keycap and clean the switch directly.

Sticky keys after a spill are a different problem. Sugary liquids leave residue that bridges contacts, and the damage often appears days later. That usually needs the keyboard opened and cleaned properly, or replaced.

## Testing a keyboard before you buy

If you are buying a used mechanical keyboard, run this test before paying, alongside the [screen test](https://www.test-webcamp.com/screen-test.html) and [mouse test](https://www.test-webcamp.com/mouse-test.html) on the same machine. It takes a minute and catches dead switches, which are the most common fault and the most expensive to fix if you cannot solder.

## Other checks

## Common questions

Why does a key light up but produce nothing when I type?

The test listens for the key code your keyboard sends, which is separate from the character your operating system produces. A key that registers here but types nothing usually means a layout or language setting problem rather than a hardware fault.

Some keys never register at all.

If a key produces nothing here, the fault is physical: debris under the switch, a failed membrane contact, or a damaged ribbon connector. Try the same key in a different application to confirm before opening anything up.

Two keys at once do not both register.

That is key rollover, and it is normal on membrane keyboards. Cheaper keyboards share wiring between groups of keys, so some combinations cannot be detected together. Mechanical keyboards with N-key rollover do not have this limit.

Why can I not test the Windows or Command key?

Your operating system intercepts some keys before the browser sees them. The Windows key opens the Start menu and certain function keys are handled by firmware, so they may not reach this page.