Keyboard test: check every key

How to test your keyboard

1. Click anywhere on this page so it receives your key presses.
2. Press each key once. It turns blue while you hold it and green once it has worked.
3. Keys that stay grey after you press them aren't reaching the computer. The list under the keyboard shows which ones are left.
4. Pick the board that matches your keyboard: Full size, No number pad or Mac. On a Mac, the Mac board is picked for you.
5. For the double-press check, type normally for about a minute, in the box or anywhere on the page.

Reading the results

Most keys at once (ghosting and rollover)

Hold down several keys together, for example W, A, Shift and Space as in a game, and watch Held now. If a key you're holding doesn't light up, your keyboard can't register that combination. This is called ghosting. Office keyboards often manage only 2 or 3 keys in some combinations; gaming keyboards usually handle 6 or more (“6-key” or “n-key rollover”).

Double-press check (chatter)

If one press of a key sometimes types the letter twice, the switch is “chattering”. It often only shows up when you type quickly, so pressing each key once isn't enough: type normally for a minute. The test flags a key when it goes down again less than 30 ms after you let go, faster than any finger. After 300 key presses with no doubles, your switches are fine. One double can be a fluke; the same key doubling twice or more is a faulty or dirty switch.

Hover over a key on the board to see how many times you've pressed it.

Key, code and key code

For developers: Key is the character or name the key produces (it depends on your keyboard language), Code is the physical key (KeyboardEvent.code), and Key code is the older numeric keyCode many scripts still use.

Testing a Mac keyboard

The Mac board matches a MacBook or Magic Keyboard with the US layout: fn, control, option and command along the bottom, arrows in one row, and no Insert, Home or Print Screen keys. A few things work differently on a Mac:

• F1 to F12 change brightness and volume by default, and the browser doesn't see those. Hold fn while you press them, or turn on “Use F1, F2, etc. keys as standard function keys” in System Settings > Keyboard > Keyboard Shortcuts > Function Keys.
• fn (the globe key) is handled by macOS itself, so browsers never see it on its own. To test it, hold fn and press an arrow key or delete: fn + ← sends Home and fn + delete sends forward delete, keys a MacBook doesn't have, so fn lights up.
• Caps lock ignores very quick taps on Mac keyboards, to stop it turning on by accident. Press it a little longer.
• Command shortcuts still work, so Command+Q quits the browser and Command+W closes the tab. Avoid them while testing.
• Touch ID and the power key can't be tested in a browser.

MacBooks from about 2016 to 2019 with the very thin “butterfly” keyboard are known for keys that stick or type twice. The double-press check above shows whether yours does.

Keys that a browser can't test

• Fn on most Windows keyboards is handled inside the keyboard itself, so the computer never sees it on its own. Test it by pressing Fn together with a key that uses it.
• The Windows key opens the Start menu, and Print Screen often only reports when it's released. Both may light up only briefly.
• Media and volume keys, and some laptop special keys, go straight to the operating system and may not show up here.

A key doesn't work? Try these fixes

Dirt under the key

Crumbs and dust are the most common cause of a dead or sticky key. See how to clean keyboard keys below.

Windows settings

If keys only work when held down, or repeat oddly, open Settings > Accessibility > Keyboard and turn off Filter Keys and Sticky Keys. If the number pad doesn't type numbers, press Num Lock.

Mac settings

If keys need a long press, open System Settings > Accessibility > Keyboard and turn off Slow Keys.

Wrong characters

If a key works but types a different character, your computer is set to a different keyboard language. The Code line above shows which physical key you pressed, so you can tell a layout problem from a broken key.

A key types twice

1. Clean the switch: blow compressed air around the key. On a mechanical keyboard, pull the keycap off and blow straight into the switch.
2. If your keyboard has its own software (or QMK or VIA firmware), look for a debounce setting and raise it a few milliseconds. Low debounce makes switches more likely to double.
3. On a hot-swap mechanical keyboard, swap the faulty switch for a new one.
4. On a new keyboard, contact the seller with the result of the double-press check: a key that types twice is a hardware fault.
5. As a stopgap on Windows, Filter Keys (Settings > Accessibility > Keyboard) can ignore keystrokes repeated within a short time. It also slows down deliberate double letters, so it's not a long-term fix.

Keyboard not typing at all?

1. Check here first. If keys light up on this page, the keyboard works: click into the box you want to type in, and check the app's language setting.
2. Wired keyboard: unplug it and plug it into another USB port, directly rather than through a hub.
3. Wireless keyboard: check the power switch, charge it or change the batteries, and plug the receiver back in. For Bluetooth, remove the keyboard from your Bluetooth settings and pair it again.
4. Windows: holding the right Shift key for 8 seconds turns on Filter Keys, which can make the keyboard seem dead. Turn it off in Settings > Accessibility > Keyboard. If that's not it, open Device Manager, right-click the keyboard under Keyboards, choose Uninstall device and restart: Windows reinstalls it.
5. Mac: in System Settings > Accessibility, turn off Slow Keys (under Keyboard) and Mouse Keys (under Pointer Control), which makes some letter keys move the pointer instead of typing.
6. Restart the computer. It clears a stuck driver more often than you'd expect.

Keyboard delay or lag

1. Filter Keys on Windows adds a delay before a key press counts. Turn it off in Settings > Accessibility > Keyboard. On a Mac, check Slow Keys in System Settings > Accessibility > Keyboard.
2. Repeat delay: if holding a key takes long to repeat, shorten the delay. On Windows, press Windows+R, type control keyboard and move the Repeat delay slider. On a Mac, use Delay until repeat in System Settings > Keyboard.
3. Wireless keyboards lag when the battery is low or the signal is weak. Move the receiver closer, for example with a USB extension cable, and away from USB 3 ports and Wi-Fi routers, which can interfere. Bluetooth keyboards are usually a little slower than ones with their own receiver.
4. Only in one app? If keys light up here straight away but lag in Word or a browser with many tabs, the app or a busy computer is the problem, not the keyboard. Check Task Manager or Activity Monitor.

How to clean keyboard keys

1. Unplug the keyboard or turn it off. Shut a laptop down.
2. Turn it upside down and tap the back gently to shake out crumbs.
3. Blow compressed air between the keys in short bursts, holding the can upright and the nozzle at an angle.
4. Wipe the keys with a cloth or cotton bud slightly damp with isopropyl alcohol (70% or more). Never pour liquid onto the keyboard.
5. On a mechanical keyboard, pull the keycaps off with a keycap puller, wash them in warm soapy water and let them dry completely before putting them back. Don't pull keys off a laptop: their clips break easily.
6. After a spill, unplug or shut down at once, turn the keyboard upside down to drain, and let it dry for at least a day. Sugary drinks leave sticky keys that may need a professional clean.

Questions

Setting up for calls or streaming? Check your microphone, webcam and speakers too.