How to use the keyboard tester
- Open this page. The keyboard tester runs in your browser, so there’s nothing to install.
- Pick your layout and size. ANSI is the US layout. ISO has a tall Enter key and an extra key next to left Shift. Mac has Cmd and Option keys.
- Click the keyboard, or press Tab to reach it and then Enter. Every key you press now goes to the test, not to the page.
- Press every key once, including both Shift, Ctrl and Alt keys. Each key lights up in color when it registers, with a small glowing dot in its corner, and stays lit.
- Press Show untested to see which keys are left.
- Press Finish and Copy report. Any key you didn’t press is listed as not registered.
Press Esc twice to leave the test area. A full-size keyboard takes about 2 minutes. Tested keys stay marked if you reload the page, until you close the tab, so you can take a break and continue.
How the keyboard test works
When you press a key, your browser reports two things: code, the physical key, and key, the character it types. This keyboard test reads code, so left and right Shift are separate keys, and numpad digits light up even with Num Lock off.
Unlike a key tester app or a keyboard checker you download, this keyboard tester online needs no install and no permissions. It only sees keys that reach the browser:
- Fn works inside the keyboard and never sends its own code. Fn and Touch ID keys are drawn dashed.
- Some media keys (brightness, volume on some laptops) are handled by the keyboard or the operating system.
- System shortcuts such as the Windows key, Alt+Tab and Ctrl+W are taken by Windows or the browser. In Chrome and Edge, press Capture system keys: the test goes full screen and receives those keys too. Press and hold Esc to exit.
This keyboard test checks one key at a time. To check many keys held together, as games need, use the rollover and ghosting tests listed at the end of this page.
Understanding your results
| What you see | What it means | What to do |
|---|---|---|
| Key lights up with a dot in its corner | The key works. | Nothing. |
| Key never lights up | The key isn’t registering. | Press it again firmly, then see the fixes below. |
| A different key lights up | The layout doesn’t match, or a remapping tool changed it. | Check the layout, and pause PowerToys or Karabiner-Elements. |
| Amber key and “registered twice” | Chatter: one press counted twice. | Clean the switch, or replace it on a mechanical keyboard. |
| “Still pressed” | The key is stuck down, or you’re holding it. | Lift the keycap gently and clean under it. |
| A key under Other keys | A key outside this layout, such as F13 or a media key. | Nothing: it works, it’s just not on the drawing. |
Windows sends Print Screen when you release it rather than when you press it. It still counts.
If several keys in one row or column fail together, the problem is usually the keyboard’s circuit or its cable, not the switches. A single dead key is usually dirt or a worn switch.
What key am I pressing?
The panel under the keyboard shows what your browser received for the last key. key is the character, such as “a” or “Shift”. code is the physical key, such as KeyA or ShiftLeft. You also see the old keyCode number, the key’s location and any modifiers you held. Developers can press Copy as JSON to paste the values into code or a bug report.
How to fix keys that don’t work
- Unplug and reconnect. Try another USB port. For Bluetooth, remove the keyboard from your device and pair it again.
- Blow out dust. Hold compressed air at an angle and sweep along each row.
- Clean under the keycap. On a desktop keyboard, pull the keycap straight up with a keycap puller. On a laptop, only lift keys if the maker’s manual shows how: the clips break easily.
- After a spill, unplug the keyboard or shut down the laptop at once. Turn it upside down and let it dry for 24–48 hours before you power it on.
- For chatter, clean the switch first. On a mechanical keyboard, replace the switch, or raise the debounce time in the keyboard’s software or firmware.
- Pause key remapping tools, such as PowerToys or Karabiner-Elements, then test again.
- Run the laptop’s own hardware check. Many laptops include a diagnostic that runs before Windows starts. Examples are Dell’s SupportAssist pre-boot check (F12 at startup) and HP PC Hardware Diagnostics (Esc, then F2). Lenovo ThinkPads open UEFI Diagnostics with F10, and IdeaPad and Legion laptops reach their diagnostics through the Novo button. If a key fails there too, it’s a hardware fault.
Test again after each step, so you know which fix worked. For a warranty claim, keep the copied report and a short video of the key failing.
Testing laptop, Mac and compact keyboards
Testing a laptop keyboard
On many laptops, F1–F12 control brightness and volume by default. To test them as F-keys, hold Fn while you press them, or turn on Fn Lock (often Fn+Esc). Keyboards without a numpad should use the TKL size. If a laptop key fails here but works on an external keyboard, the laptop’s keyboard or its ribbon cable is at fault.
Keyboard tester on a Mac
Pick the Mac layout: it labels Cmd, Option and Control, and shows the fn and Touch ID keys as dashed. On a Mac, F1–F12 act as media keys unless you hold fn, or turn on “Use F1, F2, etc. keys as standard function keys” in System Settings › Keyboard › Keyboard Shortcuts › Function Keys. macOS sends no key-up for keys pressed while Cmd is held, so the tester releases them when Cmd comes up. Caps Lock counts as soon as you switch it on.
60%, 65%, 75% and TKL keyboards
Compact keyboards reach missing keys, such as arrows or F-keys, through an Fn layer. The keyboard sends a normal code for each layer key, so test those too. Hold Fn, press the layer key and watch it light up or appear under Other keys. If the extra ISO key next to left Shift lights up while ANSI is selected, the tester offers to switch to ISO.
Which keyboard test do I need?
This keyboard tester checks each key on its own. If keys only fail when you press several at once, you need a rollover or ghosting test instead. Pick the row that matches what’s going wrong:
| What happens | Test to use |
|---|---|
| A key doesn't type or types the wrong character | Keyboard tester (above) |
| A key types twice or repeats on its own | Keyboard tester chatter hint |
| You want to know if it's 6KRO or NKRO | N-Key Rollover Test |
| Mouse buttons or scroll wheel misbehave | Mouse Test |
| Controller buttons or sticks misbehave | Gamepad Tester |