Keyboard Test

How to test your keyboard

Wondering how to test keyboard keys online without installing anything? It only takes a minute — follow these steps in order and you'll have a clear picture of exactly which keys are working.

1. Click anywhere on this page.

   Your browser needs the page focused so it can pick up key presses — just clicking once on the tester panel above is enough.

2. Work through every key, one by one.

   Start at Escape and move across each row. A key turns green the moment it registers, and it stays that colour so you don't lose track of what you've already checked.

3. Don't skip the modifier keys.

   Shift, Ctrl, Alt and the Windows/Command key fail more often than people expect, mostly because they get less individual attention during normal typing. Press left and right versions separately — they're wired independently.

4. Compare the count to your keyboard.

   The counter at the top tracks how many keys have responded. A compact or laptop keyboard won't have a numpad, so don't worry if you never reach the full total.

Who tests a keyboard, and why

People land on this page for a handful of different reasons, and the reason usually shapes what they're checking for.

Gamers run this test right after a match where a key clearly didn't register — testing WASD and the keys around it tells them in seconds whether it was the keyboard or just bad reflexes. Programmers and writers who type for eight-plus hours a day tend to notice a key degrading gradually, long before it fails outright, and use this as a quick health check rather than waiting for a full breakdown. Plenty of people specifically test a keyboard before buying a laptop — anyone buying second-hand runs the full board once before handing over payment, since a missing or double-typing key is far easier to negotiate over in person than to discover a week later. IT teams setting up a batch of new machines do the same thing across a whole stack, checking each one in under a minute instead of assuming they're all fine out of the box. And after a spill, a drop, or a few months of dust buildup, this is usually the fastest way to find out exactly which keys took the damage, rather than guessing from how typing feels. Anyone buying a laptop or setting up a new machine often runs our Mouse Test right alongside this one, to check the whole input setup in a single pass.

How this keyboard test actually works

This tool listens for two low-level browser events — keydown and keyup — that fire the instant you press or release any key, regardless of what you're typing into. Each key on the screen is just a styled box wired to one specific key code; when that code fires, the box's color flips and stays flipped. There's no text box capturing what you type and no log of keystrokes kept anywhere, which is worth knowing if you were ever wary of typing near an unfamiliar "keyboard tester" — this one has nothing to send home even if it wanted to, since the whole thing runs in memory in your browser tab and disappears the moment you leave the page.

Troubleshooting, matched to what you're actually seeing

Nothing registers, no matter what you press

1. Click directly on the tester panel first.

   If the page itself isn't focused, your browser has nowhere to send the key events. This is the single most common cause of "the tester isn't working."

2. Check the cable or wireless connection.

   Try a different USB port, or re-pair a wireless or Bluetooth keyboard from scratch rather than assuming a stale pairing is still good.

3. Test the keyboard on a second device if you can.

   This is the fastest way to split the problem in half — if it doesn't work anywhere, it's the keyboard; if it works elsewhere, something on this computer is blocking it.

Only one or two specific keys are dead

1. Rule out debris first.

   Turn the keyboard over and tap the back, then follow up with compressed air angled into the gap around that specific key.

2. Check whether it's a modifier key.

   Shift, Ctrl, Alt, and the Windows/Command key each have independent left and right switches. Confirm you're testing the correct side — it's easy to assume both sides work when you've only ever pressed one.

3. Suspect the switch itself if cleaning doesn't help.

   A key that was fine yesterday and dead today, with no spill or drop in between, usually points to a worn or failed switch rather than a settings problem.

4. Check for a remapped key if you own a gaming keyboard.

   Software like Logitech G HUB, Razer Synapse, or Corsair iCUE can silently remap or disable a key through a saved profile — worth checking before assuming it's a hardware fault.

A key types twice, or the wrong character shows up

Double-typing (often called ghosting) is almost always either a debounce issue on an aging switch or a sign the key is stuck slightly and re-triggering. The wrong-character version is different — that's a software layout mismatch, not a hardware fault, and the fix is entirely in your settings (see below).

Accessibility settings that secretly change how your keyboard behaves

Before assuming a key is broken, it's worth ruling out a setting that's easy to switch on by accident — usually by holding a key a little too long.

Windows: Filter Keys and Sticky Keys

Holding Shift for eight seconds prompts Windows to offer turning on Filter Keys, which deliberately ignores brief or repeated keystrokes — exactly the symptom people mistake for a dead or double-typing key. Check Settings → Accessibility → Keyboard and make sure Filter Keys and Sticky Keys are both off unless you intentionally use them.

macOS: Slow Keys and key repeat rate

Under System Settings → Accessibility → Keyboard, "Slow Keys" adds a deliberate delay between a press and when it registers, which can feel identical to an unresponsive key. Separately, System Settings → Keyboard → Key Repeat controls how fast a held key repeats — set too slow, it can feel like the keyboard is lagging behind your typing.

Linux: keyboard repeat and layout via xset / settings

Most desktop environments expose repeat rate and delay in their own Keyboard settings panel, but they all sit on top of X11's xset r settings underneath. Running xset q in a terminal shows your current auto-repeat status if you want to confirm nothing unusual is set at that layer.

Keyboard problems at a glance

A quick reference for matching what you're seeing to what's probably going on — useful if you want the short version before reading the fixes in detail further down.

A note on keyboard layouts

The virtual keyboard above follows a standard US ANSI layout, which is the most common one worldwide. If your physical keyboard uses an ISO layout — common across much of Europe — you'll notice a couple of differences: your Enter key is taller and L-shaped, and there's an extra key next to the left Shift.

That difference is only cosmetic for this test. Every key still sends its own signal regardless of where it physically sits, so a key in a slightly different spot on your keyboard will still light up the matching key here. If a press lands on the wrong letter entirely rather than just a different position, that's a layout setting in your OS, not something wrong with the hardware — see the fix below.

Keyboard switch types compared

Not every keyboard registers a key press the same way, and it helps to know which type you're testing, since that changes both what a "stuck" key feels like and how it should be fixed.

Key rollover and ghosting, explained

If you're a gamer, you've probably run into this: you hold down three or four keys at once during a fast sequence, and one of them just doesn't register — not because it's broken, but because of how the keyboard itself is wired.

Most keyboards scan their keys in a grid, row by row and column by column, rather than wiring every single key independently. Press enough keys in the wrong combination at the same time, and the keyboard genuinely can't tell which ones are down — that's called "ghosting," and it's a hardware limitation, not a fault with any individual key. Manufacturers work around this with anti-ghosting on specific, commonly-used combinations, or with full N-key rollover (NKRO), which scans every key independently so any number of simultaneous presses registers correctly.

You can run a keyboard key rollover test with this tool the same way: hold down several keys in a cluster at once — WASD plus Shift and Space is a good real-world test — and watch which ones light up. If a key you're physically holding down doesn't light up while others do, that's rollover, not a broken switch, and it'll behave the same way every time you repeat that exact combination. If it's inconsistent instead — sometimes registering, sometimes not — that points back to a hardware fault rather than a wiring limit.

Testing a laptop keyboard vs. an external keyboard

This key tester works identically either way, but what you do with the result differs quite a bit.

On an external keyboard, a failing key is usually a part swap away from fixed — you can often replace a single switch or keycap, or in the worst case replace the whole keyboard for relatively little money. A laptop's keyboard is built into the chassis and wired through a thin ribbon cable to the motherboard, which makes even a single dead key a more involved repair — sometimes the entire keyboard assembly needs replacing rather than just one switch.

That difference matters most when you're buying used. On a laptop, run this test before you commit, since a keyboard replacement can eat up a meaningful chunk of what you paid for the machine. On an external keyboard, a couple of iffy keys are a much smaller risk, and they're often fixable yourself with a keycap puller and a can of compressed air.

More tools on ProDeviceTest

Troubleshooting a whole setup rather than just the keyboard? These run the same way — instant, no download, right in your browser.

• Mouse Test — check clicks, scroll, and cursor tracking
• Sound Test — confirm your speakers or headphones play correctly on both channels
• Webcam Test — verify your camera before a call
• Touch Screen Test — check for dead zones on touchscreens
• All Device Tests — the full category