How to use this keyboard test
- Pick the keyboard size that matches yours: full size, tenkeyless or 75 percent. The total and the on-screen keys change with it.
- Press Start test mode. From this moment the page captures every key, so Tab, Space, Backspace, the F-keys and the arrows no longer scroll the page or move focus.
- Press each key once. It lights up while held and keeps a tick afterwards. The counter shows how many keys you have tested, and the list underneath names the ones you have not.
- Leave test mode by holding Escape for one second, or by clicking Stop test mode with the mouse. A short tap on Escape is just a test of the Escape key. Test mode is never on until you switch it on, so you cannot get stuck in it by accident.
The readout shows what the browser reported for the last event: event.key (the character or name, which depends on your layout and modifiers),
event.code (the physical position, which does not), the legacy keyCode number, the location (standard, left, right or numpad) and how many times this key has been pressed since the last reset.
The tool decides which on-screen key to light from event.code, so a French, German or Dvorak keyboard lights the same physical positions as a US one.
Keyboard sizes the test supports
| Layout | Keys counted | What is included |
|---|---|---|
| Full size (104 keys) | 104 | US ANSI: function row, main block, Windows and Menu keys, navigation cluster, arrows and numpad. |
| Tenkeyless (87 keys) | 87 | The same without the 17 numpad keys. |
| 75 percent (83 keys) | 83 | The 74 main block keys, Delete, Home, PgUp, End, PgDn and the four arrows. Real 75 percent boards vary, so treat this as a typical shape. |
The drawing is US ANSI. Keys it lacks, such as the extra ISO key, still appear in the readout but are not counted in the total.
Keys this keyboard test cannot always see
A web page only receives the keys the browser and the operating system choose to pass on. These are marked with a dashed edge and "may not be detectable":
- Windows key and Command key. The operating system usually handles them first (Start menu, Spotlight), so the page may never see them.
- Print Screen. It often triggers a screenshot, and on some systems the page receives only the key release or nothing at all.
- Fn. On most laptops it is handled by the keyboard firmware and never reaches the computer as a key. You can only test what Fn does to other keys, such as F5 or the volume keys.
- Browser-reserved shortcuts, such as Ctrl+W, Ctrl+T and Alt+F4, cannot be intercepted by any page.
Ghosting, rollover, chatter, stuck keys and double typing
| Term | What it means | How to check it here |
|---|---|---|
| Rollover (2KRO, 6KRO, NKRO) | How many keys the keyboard can report at the same time. Many ordinary USB keyboards report up to 6 normal keys plus modifiers; gaming keyboards often advertise N-key rollover. | Hold keys down one by one and watch "Held now" and "Most held at once". When a new key stops lighting up, you have reached a limit. |
| Ghosting | A key press that the keyboard invents, or a real press that is lost, because of how the key matrix is wired. It usually shows up with certain key combinations. | Press the combination you care about, for example W, A and Space. A missing or extra key in the readout points to ghosting or a rollover limit. |
| Chatter (switch bounce) | One physical press registers more than once, usually on a worn or dirty switch. | Tap a suspect key once, firmly. "Presses of this key" should read 1 each time. A 2 or 3 after a single tap is chatter. |
| Stuck key | A key is reported as held after you let go, or really does not return. | Release everything. "Held now" should return to 0. If a key stays lit with nothing pressed, it is stuck or something is jammed under it. |
| Dead key | A key produces no event at all. | Press it several times. If it never lights and "Last key event" does not change, check the list of untested keys and try cleaning or another port. |
"Most held at once" is a rough guide only. The limit can come from the keyboard, its connection, the operating system or the browser, and this page cannot tell which. It cannot measure ghosting scientifically, only show you what arrived. Repeat a combination a few times.
How to test a laptop keyboard
Choose the size closest to yours and expect some keys on the drawing to be missing from your machine. Many laptops put media functions on the F-keys by default, so F1 to F12 may need Fn held down. If a whole row or column of keys fails together, that points to a ribbon cable or keyboard controller problem rather than worn switches.
Tips for mechanical keyboards
- Test at your normal typing speed as well as slowly. Some chatter only appears on quick, light taps.
- On a hot-swappable board, move a suspect switch to another position. If the fault follows the switch, the switch is the cause.
- Keyboards with several modes (wired, wireless, game mode) behave differently in each, so test in the mode you use.
Mac keyboards
On a Mac, the Command keys appear as the Windows keys (MetaLeft and MetaRight) and Option appears as Alt. The top row defaults to media controls, so F1 to F12 normally need Fn held down.
Keys outside the standard layout, such as Eject or the Globe key, are mostly not reported to web pages.
Why Tab, Space and the arrows do not scroll in test mode
During a test the page has to cancel the default action of each key press, otherwise Space would scroll and Tab would move focus away. It does this only in test mode, announces it when you switch it on, and always leaves a way out: hold Escape for one second, or click the Stop button. While test mode is on, shortcuts such as / and Ctrl+K are tested like any other key instead of opening site search.
FAQ
How do I test my keyboard online?
Press Start test mode, then press every key. Each one lights up while held and stays marked as tested. The list below the keyboard shows the keys you have not pressed yet.
Why does a key not light up?
Either the key is faulty, or the system keeps it for itself (Windows key, Print Screen, Fn, browser shortcuts). Try pressing it several times, then check whether it works in a text editor.
What does "most held at once" tell me?
It is the largest number of keys held together that the browser reported. If you held more than that and the extra keys did not register, your keyboard or connection is limiting simultaneous keys.
How can I tell if a key is double typing?
Tap it once and read "Presses of this key". It should say 1. A higher number after a single clean tap suggests a worn or dirty switch.
Is anything I type sent to a server?
No. The page reads key events locally and does not store or transmit them. Only your chosen keyboard size is remembered in your browser.