Keyboard Tester — Test Every Key Online
This keyboard tester shows you within seconds which keys still register and which ones are dead. Press any key and it lights up on the on-screen layout; anything that stays dark never reached your computer.
Nothing to install, no account to create. It works the same with a built-in laptop keyboard, a USB mechanical board or a Bluetooth keyboard, because it reads the same key events your operating system hands to every other application.
How to test your keyboard online
Click once on the on-screen keyboard so the page has focus, then press every key on your physical keyboard one time. Each key is marked as you press it and stays marked, so a single pass shows you which keys never responded.
Work in a fixed order — function row, number row, letters, modifiers, arrows, numpad — so nothing is skipped, and hold one key for a second to check it repeats and then stops cleanly. If a key you tapped once registers twice, that is switch bounce, and the keyboard double click test measures how far apart the two signals landed. If a key stays lit after you release it, the stuck key test shows whether the key-up event arrives at all.
A key that stays dark never reached the browser. Plug a spare keyboard into the same port: if the spare works, yours is at fault; if it does not, suspect the port, the driver or the OS.
What this keyboard tester checks
This keyboard tester listens to the browser's raw keydown and keyup events, so it sees exactly what your operating system passes to applications: the alphanumeric block, F1–F12, the numpad, arrows, Insert, Home and Page Up, both Shift, Ctrl and Alt keys, and the three lock keys.
For every press it records the key name, the browser key code and the physical location, which is how it tells left Shift from right Shift, and numpad 4 from the 4 on the number row. That location field is what makes a layout mismatch obvious straight away.
Other behaviour needs its own measurement. How many keys register at once is what the keyboard ghosting test checks; how long a press takes to become a character is the keyboard latency test; how often the board reports to the PC is estimated by the keyboard polling rate test. For raw tapping speed use the keyboard cps test, and for words per minute on real text, the typing speed test.
Testing a laptop keyboard
Laptop keyboards fail differently from desktop ones. There is no switch to swap, so the useful question is narrower: is the key dead everywhere, or only inside Windows?
HP, Dell, Lenovo and Asus laptops
Every major vendor ships its own check — HP PC Hardware Diagnostics, Dell SupportAssist and its ePSA pre-boot test, Lenovo Vantage, MyASUS on ASUS machines. Run one after this page, because a failure recorded by the manufacturer's own tool is what support accepts without argument.
Use the browser test for what those tools do badly: a fast, repeatable pass over all 80-plus keys that you can screenshot. Laptop keyboards usually lose a cluster rather than one key, and failures grouped on a layout point at the membrane or ribbon connector, not four switches that died the same week.
Is it the keyboard or is it Windows?
Restart and press the failing keys in your BIOS or UEFI setup screen. BIOS loads before any operating system driver, so keys that work there but fail in Windows mean the hardware is fine and software is eating the input — a bad driver, a vendor utility or a recent update.
If the keys fail in BIOS too, stop troubleshooting software and report it while the warranty is still alive.
Compact layouts: 60%, 65%, 75% and TKL
On a compact board, half the keys you want to test do not exist physically. Tenkeyless removes the numpad, 75% squeezes the function row and navigation cluster together, 65% drops the function row, and 60% keeps only the main block — about 61 keys against 104 on a full-size layout.
Everything else lives on a function layer. Hold your board's layer key, usually Fn, and press the position the key would occupy on a full-size layout: Fn plus the number row normally gives F1–F12, and Fn plus the right-hand letters gives the arrows, Home, End, Page Up and Page Down.
The layer key itself never appears in the keyboard tester, and that is expected. Firmware resolves the layer internally and sends only the resulting key, so watch for the F-key or arrow on screen, not the modifier.
Windows, macOS, Chromebook and Linux
The test runs in Chrome, Edge, Firefox, Safari and Brave on Windows 10 and 11, macOS, ChromeOS and Linux, because browser key events are the same everywhere. What differs is which combinations the operating system keeps for itself.
On Windows the Windows key opens Start and Alt+Tab switches applications, so neither reaches the page cleanly. On macOS, Command+Tab and Command+Space are captured by the system and the Fn/Globe key behaves as an Apple-specific modifier — the mac keyboard test covers the MacBook and Magic Keyboard differences. On a Chromebook the top row sends browser actions until you enable "Treat top-row keys as function keys".
Print Screen, media keys and vendor hotkeys are often intercepted too. If they do not appear here but still do their job, the key works — only the event is consumed before the browser sees it.
Common keyboard faults and what they mean
Almost every keyboard complaint falls into one of six patterns, and the pattern names the cause:
- A key does nothing. Dead switch, debris, or a broken trace. Several adjacent keys failing together points at the ribbon cable or a matrix row.
- A key types twice. Contact bounce from a worn switch. On a hot-swap board it is a 30-second fix.
- A key repeats forever. The key-up event never fires — a stuck key, or a repeat delay set far too short.
- A key types the wrong character. Nearly always a layout mismatch, not damage.
- Keys vanish while typing fast. Wireless interference, or rollover limits on a wired board.
- Dead in Windows, fine in BIOS. A driver or update problem, never the hardware.
Your keystrokes are never recorded
Nothing you press is stored, uploaded or logged. This keyboard tester runs entirely in your browser: JavaScript reads the key event, marks the matching key, and discards it. No text is assembled, no request carries your input, and closing the tab erases the result.
One habit still applies to every site: do not type real passwords into a page you are testing. Ordinary letters exercise exactly the same switches.
Frequently asked questions
Why are some of my keyboard keys not working?
Most often the key itself is dead: dirt, wear or a failed switch is stopping the signal before it reaches your PC. Press the key on the tester above. If it never lights up, nothing is arriving. Rule out software by trying the same key in your BIOS/UEFI setup screen, which runs without Windows drivers, or by plugging a spare keyboard into the same port. If the spare works and yours does not, the keyboard is the fault.
Why does my keyboard type two letters when I only press the key once?
Your switch is bouncing, so one physical press produces two electrical signals. This is called key chatter and it almost always means a worn or contaminated switch rather than a software bug. A very short Windows repeat delay can imitate it, so check Control Panel > Keyboard first, then run the keyboard double click test to measure the gap between the two events. Under roughly 20 ms is the switch, not your finger.
Why does one key press repeat over and over as if I am holding it down?
The key-up signal is not arriving, so your computer still believes the key is held. Two things cause it: a physically stuck key, or a typematic repeat delay set far too short. Control Panel > Keyboard > Repeat delay fixes the software half in seconds, and the stuck key test shows which of the two you have. If the key still runs away inside BIOS setup, the switch itself is jammed.
Why does my keyboard type the wrong letters?
Your active keyboard layout does not match the physical keys. A US board set to UK English swaps the quote and @ keys, and an AZERTY layout moves whole letters. Fix it in Windows language settings or macOS Input Sources. If instead a single key prints two characters at once, such as T producing GT, that is physical damage under that one key and no layout change will help.
Why doesn't the Fn key show up in an online keyboard test?
The Fn key never reaches your operating system, so no browser test can see it. It is handled inside the keyboard controller, which rewrites the scancode of whatever key you press alongside it. Test it indirectly: hold Fn and press F1 to F12, and watch whether the function keys register or the media actions fire. If brightness and volume respond, your Fn layer works.
Why does my wireless keyboard miss or duplicate keystrokes?
Radio interference or a badly placed receiver, not a broken keyboard. 2.4 GHz dongles in USB hubs, extension cables or ports beside a USB 3.0 device lose packets, which appears as dropped letters or bursts of repeats. Move the receiver to a port directly on the machine, keep it within a metre of the keyboard, and fit fresh batteries. Bluetooth boards behave the same way when Wi-Fi congestion is high.
How do I know whether my laptop keyboard is defective?
Test every key in one pass, note which ones fail, then press those same keys in your BIOS/UEFI setup screen. BIOS runs without Windows drivers, so a key that fails in both places is hardware. A key that works in BIOS but not in Windows is a driver, layout or update problem. Screenshot the failing keys before you contact support, because that is the evidence a warranty claim needs.
How many keys are on a standard keyboard?
104 on a US full-size keyboard, and 105 on the European ISO version, which adds one key beside the left Shift. Tenkeyless boards drop the numpad and land near 87 keys, 75% layouts near 84, 65% near 68 and 60% near 61. Gaming and media keyboards add macro, volume and profile keys on top, so 108 to 115 is common.
Some keys on my Chromebook keyboard are not working. How do I test them?
Test them in the browser first, then confirm with the built-in tool at Settings > About ChromeOS > Diagnostics > Keyboard > Test. Stay inside the diagnostics window while you press keys, because ChromeOS stops registering input as soon as another window takes focus. Remember that the Chromebook top row sends browser actions rather than F1–F12 unless you enable "Treat top-row keys as function keys".
My keyboard works in BIOS but not in Windows. Is it broken?
No. If it types in BIOS, the hardware is fine. BIOS uses its own minimal driver, so a keyboard that works there but not in Windows has a software fault: a corrupt driver, a recent Windows update, or a filter driver installed by vendor software. Uninstall the keyboard in Device Manager and reboot to force a clean reinstall, then remove updates installed around the date the problem started.