⌨️ Keyboard Test
Test all your keyboard keys, detect ghosting, and check key rollover. Press any key to highlight it and ensure your keyboard works perfectly!
Currently Pressed Keys
Press keys to see them here…
ID
🔍 Real-Time Key Detection
⚠️ Browser-based detection: the browser reports key events from the OS, which already applies some filtering. This shows the effective rollover of your full hardware+OS+browser stack — not raw hardware limits.
🎮 Rollover Stress Test
Guided combo testing — hold each key combination as prompted. Results show what your hardware+OS+browser reports simultaneously.
This test guides you through 8 predefined key combinations. Each combo advances only when you hold all required keys simultaneously — there is no fixed timer. A 12-second safety timeout handles the rare case where a key cannot be reached.
Press and HOLD all highlighted keys simultaneously:
🧠 Smart Keyboard Diagnostic
⚠️ Pattern-based browser inference only — not hardware-level detection. Results are estimates to guide troubleshooting.
How to Use
- Press any key on your physical keyboard to highlight it on the visual layout
- Keys turn green once tested — aim to test all keys
- Hold multiple keys at once to measure your rollover capability
- Use the Rollover Stress Test for guided combo testing
- Run the Smart Diagnostic to see patterns and troubleshooting tips
- Click "Reset All Keys" to start over
Detects mechanical switch bounce: rapid keydown events firing within milliseconds of the previous keyup on the same key. Adjust the threshold to tune sensitivity.
No chatter detected. Press and release keys rapidly — bounce events under the threshold appear here.
Records keydown→keyup duration per key. High standard deviation may indicate a sticky or inconsistent switch. Click column headers to sort.
Press and release keys to build timing data…
| Key | Count | Avg (ms) | Min (ms) | Max (ms) | Std Dev | Avg Bar |
|---|
Hold any key for 3 seconds after clicking Start. Uses median-interval analysis of browser repeat events to estimate OS key-repeat delivery rate.
⚠ Measures OS + browser key-repeat delivery rate. Raw hardware polling rate (125Hz–8000Hz) is not accessible from JavaScript.
Real-time keyboard event stream. Circular buffer (200 entries max). Timestamps are ms since page load.
Overlays press-frequency colors on the keyboard visual. Green = low frequency, yellow = moderate, red = highest. Data persists across resets.
Exports full session snapshot: key coverage, rollover results, stress test scores, and diagnostics. JSON uses a stable schema for external tooling.
Tracks WPM, keystrokes per minute, and character frequency in freestyle mode. Press Start, type naturally for any duration, then Stop to see your profile.
Live canvas bar chart of press counts per key, grouped by type. Bars update in real-time. Hover over bars to see exact counts.
Press keys to populate the histogram…
Measures time between consecutive keydown events. Reveals which key-pairs you transition fastest and slowest — useful for typing training and switch characterization. Needs 5+ presses per pair to appear.
Type sequences of keys to build transition data — at least 20 presses needed for meaningful results.
Synthesizes data from all diagnostic modules — timing patterns, rollover, chatter, repeat rate — to estimate your keyboard's likely switch technology. Run after extensive testing for best accuracy.
Real-time canvas timeline. Each lane = one key. Horizontal bars show press duration. Time flows left→right; newest events on the right edge. Scrolls automatically.
Start recording, then press keys to see the timeline.
Real rollover detection — compares expected vs. detected keys per combo. Classifies 1KRO → 2KRO → 3KRO → 6KRO → NKRO. Press ▶ Run Test, then hold each highlighted combo simultaneously. The test auto-captures the moment all required keys are detected — no button press needed.
Automatically cycles through 2-key → 10-key combinations using simulated key events to measure your keyboard's rollover ceiling. No physical key presses required — press ▶ Start to begin.
Fires 1,000 → 50,000 synthetic key events to measure dropped events, UI rendering lag, and event pipeline throughput under load.
Tracks which key pairs you press simultaneously, building a co-occurrence map via pairCounts[keyA:keyB]++. Useful for ergonomic analysis and identifying your most-used key combos. Enable the overlay to color keys by combination frequency. Note: true hardware ghosting (phantom keys from matrix design) cannot be detected from JavaScript — it would require comparing expected vs. received keys during a prompted test.
Measures browser queue latency using KeyboardEvent.timeStamp vs performance.now(). This reflects JS scheduling overhead (typically 0.1–5 ms), not hardware latency. Values are identical across all keyboards on the same machine — this measures your browser's event pipeline, not your keyboard. Computes average, min, max, and jitter in ms. Sparkline shows recent trend.
Measures the rate at which the browser dispatches keydown events by sampling intervals between rapid key presses. This reflects OS + browser event pipeline throughput, not raw USB hardware polling rate (which is not accessible from JavaScript). Type quickly to accumulate samples.
ℹ This measures keystroke cadence (keystrokes per second) — how fast you type — not USB hardware polling rate. True polling rate (125–8000 Hz) requires firmware-level tools (e.g. HWiNFO64). To estimate polling-rate proxy, hold one key and use the Repeat Rate Engine above.
Flags two presses of the same key within 30ms as potential switch bounce. Bouncing switches cause double-inputs, ghost keystrokes, and game misfires. Adjust threshold to tune sensitivity.
Tracks Shift, Ctrl, Alt, and Meta. Detects logical modifier lock errors — if a modifier stays active >3s after keyup, it's flagged as potentially stuck. Flashing red = stuck state.
Analyzes tested vs. untested key patterns to detect row/column matrix failures. Identifies silent clusters (entire row or 60%+ of a zone) and suggests failure modes. Test as many keys as possible first for best results.
Measures typing rhythm consistency via standard deviation of inter-key intervals. Lower CV% = more even rhythm. Rated Elite / Excellent / Good / Unstable. Note: this measures your typing cadence, not hardware jitter.
Live view of pressed keys, simultaneous count, detected rollover level, and modifier state. Updates on every key event with zero lag.
Measures inter-keydown intervals during rapid typing to characterize your typing rhythm. Type keys quickly and repeatedly to accumulate samples. Rolling window of 100 events. Note: This measures typing speed, not keyboard hardware latency — true hardware latency requires firmware-level tools.
🎮 Related Tools
Pair your keyboard test with our typing speed test and spacebar counter for complete input benchmarking.
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Browse all tools
⌨️ Keyboard Test – Check All Keys & Detect Ghosting
Welcome to the Keyboard Test – a free online tool to test all your keyboard keys, detect ghosting, and verify key rollover functionality.
Whether you're testing a new keyboard, diagnosing issues, or checking gaming keyboard performance, this tool provides instant visual feedback for every key press.
Perfect for gamers, programmers, and anyone who wants to ensure their keyboard is working perfectly.
⌨️ What is a Keyboard Test?
A keyboard test is a diagnostic tool that verifies each key on your keyboard registers correctly when pressed. It helps identify:
- Dead keys: Keys that don't respond
- Stuck keys: Keys that register continuously
- Ghosting: Key combinations that don't register
- Key rollover: How many simultaneous keys work
- Double inputs: Keys that register twice per press — similar to what our double click test detects for mouse buttons
👻 What is Keyboard Ghosting?
Ghosting occurs when pressing multiple keys simultaneously causes some keys to not register. This happens due to keyboard matrix limitations.
How Ghosting Works
Most keyboards use a grid (matrix) to detect keys. When certain combinations of keys are pressed, the keyboard can't distinguish which keys are actually down, causing some inputs to be "ghosted" (ignored).
Example of Ghosting
In many budget keyboards, pressing W + D + Space simultaneously might fail to register the Space key, which is problematic for gaming.
🎮 N-Key Rollover (NKRO) Explained
| Rollover Type | Simultaneous Keys | Best For |
|---|---|---|
| 2-Key Rollover | 2 keys + modifiers | Basic typing |
| 6-Key Rollover | 6 keys + modifiers | General use, casual gaming |
| 10-Key Rollover | 10 keys simultaneously | Gaming, advanced typing |
| NKRO (Full) | All keys simultaneously | Professional gaming, complex macros |
N-Key Rollover (NKRO) means the keyboard can register N keys simultaneously without ghosting. True NKRO keyboards register every key independently.
🔍 How to Test for Ghosting
Follow these steps to test your keyboard for ghosting:
1️⃣ Test Common Gaming Combinations
Press W + A + Space (common in FPS games). If all three register, test W + D + Shift.
2️⃣ Test Multiple Keys
Press 3-4 keys in different areas simultaneously. Watch the "Currently Pressed Keys" section to see if all register.
3️⃣ Test Modifier Keys
Try Ctrl + Shift + Alt + a letter key. Modifier keys usually don't cause ghosting but verify anyway.
4️⃣ Test Arrow Keys
Arrow keys often have separate circuits. Test them with other keys you use in games.
💡 Common Keyboard Problems
Dead Keys
Symptoms: Key doesn't respond at all
Causes: Physical damage, debris under keycap, broken switch
Fix: Clean under keycap, test with keycap removed, replace switch if mechanical
Stuck Keys
Symptoms: Key registers continuously without being pressed
Causes: Debris, liquid damage, broken membrane
Fix: Clean thoroughly, let dry if wet, may need replacement
Double Typing
Symptoms: Single press registers as two characters
Causes: Switch bounce (mechanical), worn membrane contacts
Fix: Adjust debounce settings (software), replace switch
Intermittent Response
Symptoms: Key works sometimes, fails other times
Causes: Loose connection, oxidized contacts, failing switch
Fix: Reconnect cable, clean contacts, replace switch
🎮 Best Keyboards for Gaming
Mechanical Keyboards
Mechanical keyboards use individual switches for each key, providing:
- Better tactile feedback
- Longer lifespan (50-100 million presses)
- Customizable switches
- Usually better anti-ghosting
- NKRO support (via USB with PS/2 adapter or native)
Membrane Keyboards
Membrane keyboards use a rubber dome and pressure pad:
- Quieter operation
- Lower cost
- Often limited to 2-6 key rollover
- Shorter lifespan (5-10 million presses)
- More prone to ghosting
Optical Keyboards
Use light-based switches instead of mechanical contacts:
- Faster response (0.2ms vs 1-3ms)
- No debounce delay
- Longer lifespan (100+ million presses)
- No contact wear
- Premium price point
🛠️ Keyboard Maintenance Tips
Regular Cleaning
- Turn keyboard upside down and shake gently weekly
- Use compressed air between keys monthly
- Remove keycaps and clean thoroughly every 3-6 months
- Use isopropyl alcohol (90%+) for stubborn residue
Preventive Care
- Don't eat or drink over your keyboard
- Wash hands before extended use
- Use a keyboard cover when not in use
- Keep pets away from your keyboard
Spill Response
- Immediately disconnect keyboard
- Turn upside down to drain
- Remove keycaps and dry thoroughly
- Let air dry for 24-48 hours minimum
- Test all keys before regular use
⚡ USB vs PS/2 for NKRO
USB Limitations
Standard USB HID protocol limits simultaneous key presses to 6 keys + modifiers. However, modern keyboards use workarounds:
- Multiple HID endpoints: Keyboard appears as multiple devices
- Custom protocols: Manufacturer-specific drivers
- USB NKRO mode: Modern implementation allows full NKRO over USB
PS/2 Advantages
- Native NKRO support without limitations
- Lower latency (interrupt-driven vs polling)
- No need for special drivers
- Becoming obsolete (few modern motherboards include PS/2)
🎯 Why Keyboard Testing Matters
For Gamers
Competitive gaming requires precise, simultaneous inputs. Testing ensures:
- WASD movement + ability keys work together
- Complex combo inputs register properly
- No input lag from faulty keys
- Macro keys function correctly
For Programmers
Developers need reliable keyboards for:
- Complex keyboard shortcuts (Ctrl+Shift+Alt+key)
- All symbols and special characters working
- Function keys for IDE shortcuts
- Long typing speed test sessions without fatigue
For Writers
Authors and content creators depend on:
- Every letter key functioning perfectly
- Consistent typing experience
- No missed or double characters
- Comfortable extended use
📱 Testing on Different Devices
This keyboard test works on:
- ✅ Desktop computers (full keyboard)
- ✅ Laptops (built-in and external keyboards)
- ✅ Tablets with external keyboards
- ⚠️ Mobile devices (limited - on-screen keyboard)
🔧 Troubleshooting Guide
Key Not Registering
- Check if it's a software issue (try another application)
- Test with different USB port or PS/2 adapter
- Remove and clean the keycap
- Test the switch directly (mechanical keyboards)
- Check for driver updates
Multiple Keys Not Working
- Check cable connection
- Try a different computer to rule out driver issues
- Check for liquid damage
- Update or reinstall keyboard drivers
- May indicate controller failure
Ghosting Detected
- Verify if keyboard supports NKRO
- Enable NKRO mode if available (often Fn+F12 or similar)
- Try USB vs PS/2 connection
- Update firmware if available
- Consider upgrading to better keyboard
💎 Premium Keyboard Features
Hot-Swappable Switches
Replace switches without soldering for customization and easy repairs.
Programmable Keys
Assign macros and custom functions to any key for improved workflow.
RGB Lighting
Per-key RGB helps identify keys in dark environments and adds personalization.
Dedicated Media Controls
Volume wheel and media keys improve multitasking efficiency.
Wrist Rest
Reduces strain during extended typing sessions.
🚀 Final Tips
- 👉 Test new keyboards immediately to catch defects within return period
- 👉 Regular testing helps identify wear before total failure
- 👉 Gaming keyboards should have at least 6-key rollover, preferably NKRO
- 👉 Keep firmware updated for best performance and bug fixes
- 👉 Document which keys have issues for warranty claims
- 👉 Save test results when buying used keyboards
Remember: A properly functioning keyboard is essential for productivity and gaming performance. Regular testing helps maintain optimal functionality.
Keyboard Test – Frequently Asked Questions
What is a keyboard test?
A keyboard test verifies that all keys on your keyboard register correctly when pressed. It helps identify dead keys, ghosting issues, and key rollover limitations.
What is keyboard ghosting?
Ghosting occurs when pressing multiple keys simultaneously causes some keys not to register due to keyboard matrix limitations. It's common in budget keyboards and can affect gaming performance.
What is N-key rollover (NKRO)?
N-key rollover is the ability to register N keys simultaneously. NKRO (full rollover) means all keys can be pressed at once without ghosting. Gaming keyboards typically offer 6-key or full NKRO.
How do I test for ghosting?
Press multiple keys simultaneously (like W + A + Space for gaming) and check if all keys register in the "Currently Pressed Keys" section. If some keys don't appear, you've found a ghosting limitation. Use the Rollover Stress Test for guided combo testing.
Why is my key not working?
Common causes include debris under the keycap, broken switch (mechanical keyboards), driver issues, or hardware damage. Try cleaning, testing another USB port, and updating drivers.
Do I need NKRO for gaming?
Most gamers need at least 6-key rollover. NKRO is ideal but not essential unless you frequently press many keys simultaneously. Competitive gamers benefit most from NKRO.
Can I use this test on a laptop?
Yes! This test works on laptop built-in keyboards and external keyboards. It helps identify issues with laptop keyboards which can be harder to repair.
What's the difference between mechanical and membrane keyboards?
Mechanical keyboards use individual switches (better feel, longer life, usually better anti-ghosting). Membrane keyboards use rubber domes (quieter, cheaper, more prone to ghosting).
How often should I test my keyboard?
Test immediately when you get a new keyboard, whenever you notice issues, after spills or drops, and periodically (every 3-6 months) to catch wear early.
Is this test free?
Yes, completely free with no downloads or registration required. Works directly in your browser on any device with a physical keyboard.