Keyboard Tester

See which keys work, catch double typing and stuck keys, and get the fix.

Runs in your browser. Nothing you enter is uploaded.

Layout

Every key is caught while the keyboard is active, Tab too. Hold Esc for a second to stop.

or just press any key

No key pressed yet.

Held now: none · Most at once: 0 · Presses: 0

Press any key to start

Each key lights up when your computer receives it. Keys that stay dark were never received.

How to use Keyboard Tester

  1. Press any key. Each key lights up when your computer receives it.
  2. Press every key once. Keys that stay dark were never received.
  3. Hold several keys at once to see how many your keyboard sends together.
  4. Read the result: it flags double presses, stuck keys, Sticky Keys and a switched layout, with the fix.
  5. Copy the report if you need to send it to support.

How it works

Every key press reaches the browser as an event that names the physical key, such as KeyA or ShiftLeft, and the character it types. The test lights up each key it receives and times every press and release. Nothing you type is saved or sent anywhere.

Key color What it means
Plain Not received yet. Press it.
Green Received: the key works.
Solid Held down right now.
Orange with a number Sent a second press from one tap (chatter). The number counts how often.
Red Held for 5 seconds or more. If you aren’t pressing it, it’s stuck.
Dashed Fn. Most keyboards handle it themselves, so browsers never see it.

The keys show what your computer types, so the letters match your layout. If they don’t match the labels on your keyboard, the wrong layout is selected (see below).

Result What it means What to do
All keys work Every key reached your computer. Nothing. If one app still ignores a key, check that app’s settings.
Typed twice from one press A second press came faster than a finger can move. Clean under the key. On mechanical keyboards, raise the debounce time or replace the switch.
Is a key stuck? A key has been held for 5 seconds. Press it firmly a few times, then clean under it.
Sticky Keys may be on Shift, Ctrl or Alt was reported as held with no key down. Turn off Sticky Keys in your accessibility settings.
Layout changed One key typed two different characters. Switch back to your layout and remove the ones you don’t use.
Num Lock is off The number pad types arrows instead of numbers. Press Num Lock.
F keys in media mode Volume or play keys arrived, but no F1–F12. Hold Fn, or turn on Fn Lock.

When a key doesn’t light up

  • One key: press it firmly in the middle. If it works only when pressed hard, switch off the keyboard and blow compressed air under it.
  • F1–F12 or the top row: on most laptops these control volume and brightness first. Hold Fn while you press them, or turn on Fn Lock (often Fn + Esc).
  • Short presses ignored: Filter Keys in Windows (Settings → Accessibility → Keyboard) and Slow Keys on a Mac make the computer skip quick taps. Turn them off.
  • A row or block of keys: on a laptop, that points to the internal cable; on an external keyboard, try another USB port, cable or receiver.
  • The Windows key: many gaming keyboards have a Win Lock key or game mode that switches it off.

Double typing (chatter)

A switch that is dirty or worn can bounce, sending two presses for one tap. The test flags any second press that arrives less than 40 ms after you let go, which no finger can do, and the key log shows the exact gap. Fast deliberate double taps stay well above that.

If letters double only when you rest on a key, that’s key repeat, not chatter. Open Key log and details, hold a key, and check when repeat starts. Lengthen the repeat delay in Windows (Control Panel → Keyboard) or on a Mac (System Settings → Keyboard) if it starts too soon.

Ghosting and key rollover test

Hold several keys at once: Most at once shows how many your keyboard reported together. When a key you hold doesn’t light up, the keyboard can’t send that combination. Office keyboards often drop keys in some combinations of three or more. Standard USB mode sends up to six keys plus the modifiers, and keyboards with n-key rollover send every key. Some gaming keyboards need a setting or shortcut to turn n-key rollover on.

Keys type the wrong characters

Your computer turns each physical key into a character using the layout you selected. When the layout doesn’t match the keyboard, “ and @ swap, or Y and Z trade places. On Windows, Alt + Shift and Windows key + Space switch layouts, so one slip changes them. Press Windows key + Space to pick the right one, and remove layouts you don’t use in Settings → Time & language → Language & region. On a Mac, use the input menu in the menu bar.

Keys the browser or system keeps

  • Fn is usually handled inside the keyboard, so no browser sees it.
  • Ctrl+W, Ctrl+T and Ctrl+N close or open tabs and windows. Test Ctrl and the letters separately.
  • The Windows key opens the Start menu, but the press still counts. Alt+Tab switches windows, so test Alt and Tab separately.
  • Print Screen sends only a release on Windows. The test counts it.

Full screen (Chrome and Edge) asks permission to catch more of these keys, such as Esc and Alt+Tab. Hold Esc to leave it.

Questions

How do I test if my keyboard is working?

Open this page and press every key once. Each key lights up when your computer receives it, so a key that stays dark was never received. The counter shows how many keys of your layout work, and the result lists the missing ones.

Why is my keyboard typing double letters?

Usually a dirty or worn switch "chatters": it sends a second press a few milliseconds after the first. The test flags any second press that comes faster than a finger can move and shows the gap. Cleaning under the key often fixes it; on mechanical keyboards, raise the debounce time or replace the switch.

Why are some keys on my keyboard not working?

Dirt under the keys, Filter Keys in Windows, or an F key that needs Fn are the usual causes. If several neighboring keys fail together, a laptop's internal cable or an external keyboard's port or cable is the likely problem. Keys that light up here work, so a problem in one app is that app's setting.

What is keyboard ghosting?

Ghosting is when some keys don't register while others are held, because the keyboard can only report certain combinations. Hold several keys at once: the test shows how many arrive together. Many office keyboards drop keys in some combinations of three or more, standard USB mode sends at most six keys plus Shift, Ctrl and Alt, and keyboards with n-key rollover send them all.

Why is my keyboard typing the wrong characters?

Your computer is set to a different layout than your keyboard, for example UK instead of US, or QWERTZ instead of QWERTY. Alt + Shift or Windows key + Space can switch it by accident. The keys on this page show what your computer types, and the test warns you if the layout changes while you test.

Does this keyboard test record what I type?

No. The test runs in your browser and only keeps which keys were pressed while the page is open. Nothing is sent anywhere, and closing the page clears it.

Updated October 26, 2026 · Works in current Chrome, Edge, Firefox and Safari · Runs entirely in your browser