A keyboard tester lets you verify every key on your keyboard registers correctly. Press any key to see it highlighted — tested keys stay green so you can track your progress. Useful for diagnosing stuck keys, ghosting issues, and missing keystrokes.
How to Use the Keyboard Tester
Testing your keyboard is simple — just press any key and watch it light up green on the visual keyboard layout. The tester tracks every key you press and shows you how many remain untested.
Step 1: Click on the Page First
Click anywhere on the keyboard tester page to give it keyboard focus. Once the page has focus, every key press will be detected and shown in the layout above.
Step 2: Press Keys to Test Them
Press each key on your physical keyboard. When a key is detected, it lights up in green and the "Keys Tested" counter increments. The key's name, code, and keyCode are shown in the info bar below the stats. Continue pressing all keys until they're all tested — the progress percentage tracks your coverage.
Step 3: Check for Missing Keys
Any key that remains unhighlighted after you've pressed it is either not registering or physically stuck. Common causes include debris under the keycap, a worn membrane, or a hardware defect. Try pressing the key harder or cleaning around it with compressed air.
Test N-Key Rollover
Hold down multiple keys simultaneously. The "Keys Held" counter shows how many the keyboard is detecting at once. Gaming keyboards supporting full N-key rollover (NKRO) can register all keys simultaneously. Basic keyboards may only register 6 keys at a time (6KRO), and budget models may have rollover issues in specific key combinations.
Reset and Re-Test
Click the "Reset All" button to clear all highlights and start from zero. This is useful when testing a specific section of the keyboard or when handing the keyboard to someone else to verify their keys work too.
FAQ
Is the keyboard tester free to use?
Yes, the keyboard tester is completely free with no limits. You can test as many keys as you like without signing up or creating an account. Everything runs locally in your browser — no data is sent to any server.
Why would I need a keyboard tester?
A keyboard tester helps you verify that every key on your keyboard registers correctly. It's useful for troubleshooting sticky or unresponsive keys after a spill, checking a second-hand keyboard before purchase, testing gaming keyboards for ghosting issues, or diagnosing missing keystrokes in a laptop keyboard.
What is keyCode vs key vs code?
These are three different properties in browser keyboard events. 'key' is the logical value (like 'a', 'Enter', or 'Shift'). 'code' is the physical key location (like 'KeyA', 'ShiftLeft'). 'keyCode' is the numeric code used in older browser APIs. This tester shows all three so you can identify exactly which key was pressed.
Does the keyboard tester work on all keyboards?
Yes — it uses the browser's standard keyboard event API and works with any USB, Bluetooth, mechanical, membrane, or laptop keyboard. Function keys, numpad keys, arrow keys, and media keys are all detected. Some keys like Print Screen may be intercepted by the operating system and won't register.
What is N-key rollover?
N-key rollover (NKRO) means a keyboard can detect every key pressed simultaneously, no matter how many. Gaming keyboards often advertise this. The tester shows all currently held keys at once so you can verify how many keys your keyboard can register at the same time.
How do I reset the keyboard test?
Click the 'Reset' button to clear all key highlights and start fresh. This is useful if you want to re-test specific keys or get a clean count of how many keys you've pressed.