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Keyboard Tester.
Check every key on your keyboard. Press a key and see it light up on the map, with its event.code and event.key.
Set your values
Results update as you type.
Start the test, then press each key you want to check.
Keys detected
No keys recorded yet.
Want typing speed instead of hardware testing? Try the typing speed test
FAQs
How do I find a dead key on my keyboard?
Start the test and press every key in turn. Keys turn green once they have registered at least once, so any key still unlit after you have pressed it is either dead, has a failing switch, or is being intercepted by system software before it reaches the browser.
What is the difference between event.code and event.key?
event.code identifies the physical key position and does not change with your layout or with modifiers - the key left of Backspace is always "Equal". event.key is the character actually produced, so the same physical key gives "=" or "+" depending on Shift, and different values on a non-US layout. If code is correct but key is wrong, your hardware is fine and your OS layout is the problem.
Does this test hijack my browser shortcuts?
No. Only keys that would scroll the page - space and the arrow keys - are swallowed while the test is running, and only when no modifier is held. Ctrl/Cmd combos, the function keys including F5 and F12, Tab and Escape are all passed through to the browser, so you are never trapped in the test.
Why do some keys never appear?
Media keys, Fn, and some laptop hotkeys are handled entirely by the keyboard firmware or the operating system and never generate a browser keyboard event. Their absence here does not mean they are broken. The same applies to keys captured by a global shortcut in another application.
Is this the same as a typing speed test?
No. This tool checks that your hardware registers every key correctly. If you want words per minute and accuracy instead, use the typing speed test at /productivity/typing-test.
Cite this calculator
Canonical URL: https://mathify.one/en/random/keyboard-test
Cite as: Mathify. (2026). Keyboard Tester. https://mathify.one/en/random/keyboard-test
Use Cases
Diagnose keyboard issues
Use the tester to check if all keys are working properly. Press each key and see if it registers on the map. This helps identify dead or stuck keys before replacing the keyboard.
Example: Press every key one by one to ensure each highlights correctly.
Learn key codes for development
Developers can use the tester to see the exact event.code and event.key values for each key, which is useful when implementing keyboard shortcuts or handling input events.
Example: Press 'Shift' to see event.code 'ShiftLeft' and event.key 'Shift'.
Frequently Asked Questions
- How do I use the keyboard tester?
- Simply click on the keyboard tester page and press any key on your physical keyboard. The corresponding key will highlight on the on-screen keyboard map, and the event.code and event.key values will be displayed for that key press.
- What does event.code and event.key mean?
- event.code is a physical key identifier (e.g., 'KeyA' for the A key) that doesn't change based on layout or modifiers. event.key is the character or function the key produces (e.g., 'a', 'A', 'Enter'). This helps identify which physical key is pressed and what input it generates.
- Can this tester detect stuck or dead keys?
- Yes, by pressing each key and observing if it highlights on the map. If a key doesn't highlight when pressed, it may be dead. If a key stays highlighted without being pressed, it may be stuck. The tester helps you identify such issues.
Tips & Common Mistakes
Tips
- Test all keys, including modifiers like Shift, Ctrl, and Alt, to ensure they register correctly.
- Use the tester in a well-lit environment to see the on-screen keyboard clearly.
- If a key doesn't highlight, try pressing it firmly or check for debris under the key.
- Compare the event.code and event.key values to understand how your keyboard layout affects input.
Common Mistakes to Avoid
- Pressing keys too quickly without observing the highlight, missing a dead key.
- Assuming a key is stuck when it's actually the OS repeating the key due to holding it down.
- Not testing all keys, especially less-used ones like F-keys or Print Screen.
Last updated: August 13, 2026