Keyboard Test: Free Online Key Rollover and Ghosting Checker
Test every key on your keyboard free in your browser. Check key coverage, N key rollover, ghosting on common gaming key combinations, and stuck keys, with a live visual keyboard that lights up as you type.
Press keys across your keyboard, hold several at once, and run the ghost combo checks to get a full plain language summary of your keyboard health.
Some shortcuts, such as Cmd Tab or Win L, are captured by your operating system before reaching the browser. This is normal and not a sign of a faulty key.
How to test your keyboard
Click the keyboard area to focus it
Browsers only detect key presses on a focused element, so click inside the visual keyboard box before you start typing.
Press every key
Work across the whole keyboard, letters, numbers, function row, modifiers, and arrows. Each key lights up as pressed and stays marked once tested.
Hold multiple keys for rollover
Try pressing several keys at once, for example A, S, D, F, J, K, and L together, to see your max simultaneous count and check for N key rollover.
Run the ghost combo checks
Click each combo button, then hold that exact combination for a few seconds. A failed combo usually means one key drops out when the others are held.
What this keyboard test checks
Key coverage
Tracks which physical keys have registered at least once, so you can spot a single dead key that easy typing might otherwise miss.
N key rollover
Measures the highest number of keys held down at the same time, which reveals whether your keyboard can handle demanding gaming key combinations without dropping input.
Ghosting and stuck keys
Runs specific gaming style key combinations known to expose ghosting on cheaper keyboards, and flags any key that stays held far longer than a normal press.
Understanding your results
Meets 6 key rollover or full N key rollover, the gaming mechanical standard
Functional for most typing and many games
Typical of budget membrane keyboards, may drop inputs in fast combos
Nearly every key on your layout has been confirmed working
Keep testing, low coverage usually means untested keys rather than a faulty keyboard
A key held over 5 seconds without release, retest that key on its own
Fixing common keyboard problems
- A key that never registers usually means a worn switch or a broken connection under that key, cleaning sometimes helps but replacement is often needed.
- Ghosting during a specific combo, such as dropping one key in W plus A plus S, points to the internal key matrix and is more common on cheaper membrane boards without individual key diodes.
- A single press that types the character twice, known as chatter, comes from contact bounce inside a worn switch and is different from a stuck key.
- If keys stop registering entirely, click back into the keyboard test area, since browsers only capture key events on a focused element.
- Some keyboards ship in 6 key rollover mode by default, check your keyboard software or a physical switch on the back for an N key rollover or gaming mode toggle.
Test your other gear
Input issues are not always the keyboard. Check the rest of your setup with our other tools.
Mouse Test
Check buttons, scroll wheel, and double click faults on your mouse. Open Mouse Test
Input Latency Test
Measure how quickly your inputs are registering overall. Open Latency Test
Gamepad Tester
Full button, stick, and trigger diagnostics for controllers. Open Gamepad Tester
Frequently asked questions
Why does the test need me to click the keyboard area first?
Browsers only send key events to whichever element currently has focus. Clicking the visual keyboard area gives it focus so it can capture your key presses.
What is N key rollover?
N key rollover describes how many keys a keyboard can register held down at the same time. Cheap membrane keyboards often cap at 2 or 3, while gaming mechanicals typically support 6 or more, sometimes unlimited depending on the connection.
What is keyboard ghosting?
Ghosting happens when certain key combinations produce a missing or extra keypress because of how the internal key matrix is wired. A common example is a keyboard dropping one key when three specific keys are held together.
My max simultaneous only shows 4, but my keyboard claims N key rollover. Why?
Normal typing rarely holds more than 3 or 4 keys at once, so this stat needs a deliberate test. Try pressing 6 or more keys together on purpose, for example A, S, D, F, J, K, and L at the same time.
Why did Cmd Tab or Win L not register in the test?
Certain shortcuts are intercepted by your operating system before they ever reach the browser. This is expected behavior, not a fault with your keyboard or this tool.
What does a stuck key result mean?
It means a key was detected as held for more than 5 seconds without a release event. This can be a genuine stuck switch, or a false flag if you deliberately held a key that long, retest that specific key on its own to confirm.
Does this tool detect chatter, where one press types twice?
Not directly. Chatter needs interval based analysis on repeated presses of the same key. If you suspect chatter, type a sentence in any text field and look for unwanted duplicate characters from single presses.
Will this work on a laptop keyboard?
Yes, any keyboard your operating system recognizes, including laptop scissor switch keyboards, external mechanical boards, and wireless or Bluetooth keyboards, works the same way with this test.
Some keys on my custom layout are not shown on the diagram. Is that a problem?
No. The visual layout covers the most common keys, but the tester still captures whatever key codes your keyboard sends, so coverage may read slightly differently on non standard, split, or custom layouts without affecting the rollover and ghosting checks.
Do I need to install software to test my keyboard?
No. This keyboard test runs entirely in your browser. There is nothing to download and no account is required.