Keyboard Tester — Check Every Key in Seconds

What is a Keyboard Tester?

A keyboard tester (कीबोर्ड टेस्टर) shows which keys on your keyboard are working. Every time you press a key, it lights up on a picture of a full keyboard, so you can quickly spot a dead key, a key that only works sometimes, or one that is stuck and repeating on its own. It is useful when you buy a new or second-hand laptop, after spilling something on a keyboard, before returning a keyboard under warranty, or when a gaming keyboard misses key presses.

This free tool covers the full layout — function keys, the main typing block, navigation keys, arrows and the numeric keypad — and also checks key rollover (how many keys can be pressed together). It runs entirely in your browser and nothing you type is sent anywhere.

Key Features

• Full-size keyboard map with function row, navigation keys and numpad.
• Blue while held, green once tested — easy to see what's left.
• Last key and event.code for each press.
• Keys tested counter and a list of untested keys.
• Rollover check — how many keys are held right now and the maximum.
• Key log that marks auto-repeat, useful for spotting stuck keys.

How to Use It

1. Click the keyboard picture — the border turns blue to show it is listening.
2. Press every key, row by row, from Esc to the bottom row.
3. Don't forget both Shift, Ctrl and Alt keys, the arrows and the numpad.
4. Hold several keys at once to check rollover.
5. Look for keys that are still grey, and check the log for unwanted repeats.
6. Click outside the area to use your keyboard normally again.

Reading the Results

Key Rollover and Ghosting

Rollover is the number of keys a keyboard can register at the same moment. Basic office keyboards may handle only two or three keys at once in some combinations; gaming and mechanical keyboards often advertise 6-key rollover (6KRO) or N-key rollover (NKRO), meaning every key. Ghosting is when a keyboard misses a key or reports an extra one during multiple presses, because of how its key wiring matrix works.

To test: click the area, then press and hold keys one by one — for example A, S, D, F, J, K, L — and watch "Held now (max)". If the number stops increasing even though you are pressing more keys, you have reached your keyboard's limit for that combination. Gamers often test common combinations such as W + A + Shift + Space.

Laptop Keyboards: What Can and Can't Be Tested

• Fn key: handled inside the keyboard; websites usually can't see it. Test Fn combinations by their result (for example Fn + F-key brightness changes).
• Media and brightness keys: often handled by the operating system and not passed to the browser.
• Numpad: many laptops don't have one, so those keys stay grey — that's normal.
• Pause, Scroll Lock, Insert: missing or hidden behind Fn on many laptops.
• Print Screen: some systems capture a screenshot instead of passing the key on.

What to Do About a Faulty Key

1. Clean it: turn the keyboard off or unplug it, tilt it and use compressed air around the key; gently wipe sticky keys with a slightly damp cloth (isopropyl alcohol on a cotton bud works well).
2. Check settings: Filter Keys or Sticky Keys (Windows accessibility) and keyboard layout settings can change behaviour.
3. Update or reinstall drivers for external keyboards, or try another USB port or a fresh battery for wireless ones.
4. Try another computer to see if the problem follows the keyboard.
5. Repair or replace: mechanical keyboards often allow swapping a single switch; laptop keys may need a service centre.

Buying a Used Laptop or Keyboard?

Open this tester on the device before you pay. Press every key, test both Shift and Ctrl keys, the arrows and Enter, and hold four or five keys together. Also check the touchpad and screen with our Screen Resolution Checker, the camera and microphone with the Webcam & Mic Test, and the Wi-Fi with the Internet Speed Test. Five minutes of testing can save an expensive repair.

Testing a Gaming or Mechanical Keyboard

Gaming keyboards are bought for responsiveness, so it is worth checking them properly. Press every key once to confirm it registers, then test the combinations you use in games — for example W + A + Shift + Space while holding Ctrl — and watch the maximum held count. If a key sometimes fails to light up, try pressing it at different points of the keycap; a switch that only works when pressed in the centre may need cleaning or replacement. For keyboards with on-board software, also check that macros or layers are not remapping keys, which would make the wrong key light up here.

Spotting Chattering Keys

"Chatter" is when a single press registers twice, typing letters like "tthe" instead of "the". It is common in worn mechanical switches. Press the suspect key slowly once and look at the log: two quick entries for one press means the switch is chattering. Cleaning with compressed air sometimes helps; otherwise the switch may need replacing, or keyboard software with a "debounce" setting can reduce it.

event.key vs event.code

Browsers report two names for each press. event.key is the character or action produced — "a", "A", "Enter" or a Hindi letter, depending on your layout and Shift. event.code is the physical key position — "KeyA", "ShiftLeft", "Numpad5" — the same on any layout. This tester lights keys by their physical position (code) and shows both in the log, which is handy for developers and for checking whether left and right modifier keys work separately.

Different Keyboard Layouts

The on-screen map shows a standard US-style layout because that is what most keyboards sold in India use. If your keyboard has a different layout — UK (with a larger Enter key), a Mac keyboard, or a compact 60% or 75% board — some keys will be in different places or missing entirely. That is fine: the tester identifies keys by their physical code, so a key still turns green wherever it sits. Use the log to see the exact code a key sends if you are unsure which one it is.

Privacy

Key presses are handled only inside this page to colour the keys and fill the log. Nothing is stored or sent to any server. Even so, avoid typing real passwords into any test tool — it's a good security habit.

Common Mistakes

• Not clicking the test area first — key presses go to the page instead of the tester.
• Forgetting right-hand modifier keys like right Shift and right Ctrl.
• Assuming grey numpad keys are broken on a laptop without a numpad.
• Testing Fn directly — test what Fn combinations do instead.
• Pressing keys too fast when checking for chatter — press slowly and read the log.

Quick Glossary

• NKRO / 6KRO: N-key or 6-key rollover — how many keys can register together.
• Ghosting: missed or phantom key presses during multiple presses.
• Auto-repeat: a held key sending the same character repeatedly.
• Modifier keys: Shift, Ctrl, Alt and Win/⌘.
• Chatter: one press registering as two because of a worn or dirty switch.
• Debounce: a short delay keyboards use to ignore switch bounce.

Why Use This Keyboard Tester?

It covers the full keyboard, makes untested keys obvious, checks rollover and stuck keys, and shows the technical details — free, private and with nothing to install. Once your keyboard checks out, see how fast you type with our Typing Speed Test.

Keyboard Tester — Key Facts

Frequently Asked Questions

Explore More Prompt Minds Tools

Keyboard Tester works great alongside our other free tools. Every Prompt Minds tool runs entirely in your browser — no sign-up, no uploads, no watermarks. Browse all free tools.