How to Test Your Keyboard Online
An online keyboard test is the fastest way to confirm every key on your keyboard registers correctly. Our tester listens for keydown events from the browser, then highlights the corresponding key on an on-screen layout. Any key that doesn't light up when you press it is either failing to register or is being intercepted by the browser or OS.
Start by clicking inside the tester area to give the page keyboard focus. Then methodically press every key: alphanumeric, modifier, function keys, arrows, and numpad. The on-screen layout mirrors a standard 104-key US QWERTY keyboard, so each press should correspond to a visible square lighting up green.
The tester also displays the most recent key's event data: KeyboardEvent.code (physical position), KeyboardEvent.key (character), and the legacy keyCode. This is useful for developers writing custom key bindings and for diagnosing unusual keyboard layouts.
Progress is tracked in real time so you don't lose count. After testing every key, the count tells you exactly how many of the 104 standard keys responded: a fast way to verify a new mechanical keyboard or one returning from cleaning.
What Is Keyboard Ghosting and How Do You Test for It?
Keyboard ghosting is when multiple simultaneous key presses fail to register because the keyboard's electrical matrix cannot distinguish the combination. Membrane keyboards typically guarantee only 6-key rollover (6KRO), meaning at most 6 keys at once are reliably detected.
To test for ghosting, hold down 3, 4, then 5 keys at the same time and watch which ones light up on our tester. Common ghosting test combinations include W+A+S+D+Shift+Space (for FPS gaming) or J+K+L (for typing tests). If pressing 4+ keys causes one to drop, your keyboard is ghosting.
Gaming keyboards advertise NKRO (N-key rollover) or '6KRO over USB' to signal anti-ghosting hardware. Mechanical keyboards with diode-isolated switches achieve true NKRO. Even some membrane keyboards have anti-ghosting on the WASD cluster specifically for gaming.
If you discover your keyboard ghosts at combinations you actually use, the only fix is a hardware upgrade. Software cannot work around an electrical matrix limitation: the events never reach the OS in the first place.
Why Are Some Keys Not Working?
When a specific key doesn't register on our tester, the cause is almost always one of: debris under the keycap, a worn-out membrane or switch, a damaged ribbon cable inside the keyboard, an OS keyboard layout mismatch, or the browser intercepting that particular key.
First rule out browser interception. F11 is fullscreen toggle, F12 opens DevTools, Ctrl+W closes the tab, Ctrl+T opens a new one. Test these in a plain text editor like Notepad or TextEdit: if they work there but not in the browser, the browser is hijacking them.
Next, try the failing key in a different browser. If it works in Firefox but not Chrome, it's a browser extension or shortcut. Disable extensions one by one to identify the culprit.
If the key fails in all software, it's likely a hardware issue. For mechanical keyboards, lift the keycap with a puller and inspect the switch for debris or damage. Compressed air can dislodge dust; isopropyl alcohol on a cotton swab cleans contact points. For membrane keyboards, disassembly is rarely cost-effective: a replacement keyboard is usually cheaper than repair.
Mechanical vs Membrane Keyboards
Mechanical keyboards use an individual switch under every key, typically rated for 50–100 million presses. Each switch has discrete contacts that close when pressed, giving consistent actuation force and tactile feedback. Common switch types include Cherry MX Red (linear), Brown (tactile), and Blue (clicky tactile).
Membrane keyboards use a single rubber dome layer over a printed circuit. The dome collapses under pressure to bridge two contact points. They're cheaper, quieter, and lighter, but lifespan is typically 5–10 million presses per key and the typing feel is mushy compared to mechanical.
For heavy typists, mechanical keyboards last 10x longer and remain consistent across their lifespan. Membrane keyboards begin to feel uneven as some domes wear faster than others.
Repairability differs too. A failed mechanical switch can be desoldered and replaced (hot-swap PCBs make this trivial). A failed membrane keyboard is usually scrap: the dome layer is one piece and replacing it costs more than a new keyboard.
Gamers prefer mechanical for consistent actuation and N-key rollover. Office users often prefer quiet membrane or low-profile mechanical to avoid disturbing coworkers.
How to Clean a Stuck Keyboard Key
Stuck keys are usually caused by debris (crumbs, dust, hair) wedged under the keycap. The fix depends on whether the keyboard is membrane or mechanical, but the general procedure is similar.
For mechanical keyboards: unplug the keyboard, use a keycap puller to remove the affected key (do not use pliers: you'll scratch the keycap). Inspect the switch for obvious debris and use compressed air to blow it out. If the switch still sticks, apply 99% isopropyl alcohol to a cotton swab and gently clean the switch stem. Let it dry fully (10 minutes) before replacing the keycap.
For membrane keyboards: unplug first, then carefully pop the affected key off (most lift straight up with gentle pressure on opposing corners). Clean underneath with compressed air and a slightly damp microfiber cloth. Avoid soaking: moisture under the membrane will short the keyboard.
For liquid spills (the most common cause of stuck-key chaos): unplug immediately, turn the keyboard upside down to drain, and let it dry for at least 48 hours before reconnecting. Sugary or sticky liquids almost always require full disassembly to clean properly.
Testing Gaming Keyboards for Anti-Ghosting
Competitive gaming requires specific keys to register simultaneously without dropouts. The standard FPS test pattern is W+A+S+D+Shift+Space+Ctrl: 7 keys held at once. A keyboard with full N-key rollover registers all 7 on our tester; a 6KRO keyboard drops at least one.
Fighting game players test diagonals plus attack buttons. Rhythm game players test wide-spread clusters across the keyboard. Test the combinations you actually use, not just the standard ones.
Most modern gaming keyboards (Razer, Corsair, SteelSeries, Logitech G series, Ducky, Keychron) advertise full NKRO over USB. Older models or budget options often advertise '6KRO USB / NKRO PS/2': they technically support NKRO but only over the deprecated PS/2 connector.
If you discover ghosting on a gaming keyboard you already own, check the firmware. Some keyboards ship in 6KRO mode for compatibility and require a key combination (Fn+N typically) to enable NKRO. Check your model's manual.