---
title: "How to test your keyboard and find dead keys | ToolSugar"
description: "Test every key on your keyboard online, see the key and code values your browser reports, and learn why some keys never show up."
canonical: https://toolsugar.com/blog/how-to-test-a-keyboard
image: https://toolsugar.com/og.png
---

# How to test a keyboard and find keys that do not work

Updated 2026-11-09

To test a keyboard, press each key and check that something registers. Keyboard Tester shows an on-screen keyboard and marks every key you press, with the event key and event code your browser reports. It also logs recent presses and counts keys held at once. It runs in your browser and saves nothing.

[Open Keyboard Tester](https://toolsugar.com/tools/keyboard-tester)

## Test your keyboard in four steps

Work across the board in rows so you do not skip a key.

1. Click the keyboard area so it has focus.
2. Press the keys you want to test and watch them get a check mark.
3. Read the Last key line and the log for the exact key and code values.
4. Press Reset to start over.

## Find a dead key

A key that never gets a check mark after several firm presses is likely dead or blocked. Press it a few times, then try a different app to rule out a software setting. If it works elsewhere, the cause is the page or the browser.

On a laptop, a stuck or non-responding key is often dirt under the cap. Cleaning it can bring it back.

## Keys a web page cannot see

The operating system or browser handles some keys first. Power and Fn usually do not reach the page, and some system shortcuts stop there too. A missing check mark on those keys does not mean the key is broken.

The on-screen layout is US style, with a function row and arrow keys. It has no numeric keypad and no Insert, Delete, Home, End or Page keys, though those still appear in the Last key line when you press them.

## Key and code values for developers

event.code names the physical key, such as KeyA, whatever the layout. event.key gives the character produced, such as a or A, and it changes with Shift and the language layout. Bind game controls to code and text shortcuts to key. The log helps when you remap a key in software. Press the key, copy the code from the log, and use that exact value in your config. On a different language layout, the same physical key reports a different key value but the same code.

## How many keys register at once

The tool shows how many keys are held right now. Many keyboards drop some combinations when several keys are pressed together. Hold keys down one by one and see where the count stops climbing. If the count stops at a low number, the keyboard may share wiring between keys.

## Questions

### Why does a key not light up?

It may be dead, or the system may handle it before the browser. Click inside the tester first, since keys only register while it has focus.

### Can I test a mechanical keyboard for ghosting?

You can see how many keys register together, which hints at it. The tool does not claim a formal rollover test.

### Does the tester record what I type?

It logs recent presses on the page only. Nothing is sent or saved, and Reset clears the marks.

### What should I do if several keys fail the test?

Check the cable and try another USB port. On a wireless keyboard, replace the batteries and pair it again. Plugging in a keyboard you know works tells you whether the fault is the keyboard or the computer.

[Open Keyboard Tester](https://toolsugar.com/tools/keyboard-tester)

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