Keyboard Tester

A diagnostic, not a high score

People land on a keyboard tester because something feels wrong: a letter that does not fire in a game, a sticky spacebar, a laptop that types “t” twice, a numpad that died after a move. This page is the fastest way to see it. A full QWERTY layout sits on the screen, including the function row, modifiers, arrows, the nav cluster, and a numpad. Each physical key-down lights its counterpart and then marks it permanently as tested in a second color. A counter tells you how many keys have not been heard from yet. Reset clears the map so you can do it again after you reseat a cable.

We listen to the browser’s `keydown` `code` values (KeyA, Space, NumpadEnter) rather than the character that would be typed. That way Shift+A still lights KeyA, and a dead switch is a dead switch even if an overlay tool is remapping glyphs. Caps Lock, Num Lock, and Scroll Lock are included. If a key never lights, the OS did not send us an event — the switch, the matrix, the firmware, or the OS hook is the suspect, not this page.

What this page will not do

It will not flash firmware, it will not remap keys, and it will not tell you whether a mechanical switch is ‘scratchy.’ It answers one question: did a key-down event reach the browser? That is the question people actually have when they search “keyboard tester” at midnight. After you find the dead key, the next step is a can of air, a different USB port, or a replacement. If every key lights and the problem is in one game only, the bind is in the game.

When you are done, the natural next clicks on this site are the typing test (now that you trust the board) and the double click test if the mouse is the other thing acting up. A surprising number of “my keyboard is broken” tickets are a failing mouse switch sending extra clicks into a text field.

What the colors mean

How to improve your score

• Test modifiers on their own. Hold Shift, Ctrl, Alt, and Meta one at a time. Combos can hide a dead modifier behind a working letter key.
• Do the numpad with Num Lock both ways. Some boards send different codes with Num Lock off. Toggle it and walk the pad again if a number never lights.
• Try another cable before you buy a board. A flaky USB-C cable drops the whole matrix, which looks like “every other key is dead.” Swap the cable, then reset this page.
• Ghosting is real on cheap membranes. Three keys down at once and a fourth that will not light is often NKRO / ghosting, not a failed switch. Test keys one at a time to separate the two.

FAQ

Try a related test

• Double Click Test — Catch a failing mouse switch. Intervals under 80ms get flagged.
• Typing Speed Test — Measure your WPM and accuracy on real English words.
• Spacebar Speed Test — How many spacebar presses can you land? Live presses per second.