Is this keyboard tester safe to use? Does it log my keystrokes?

Completely safe. This tool runs entirely client-side in your browser using JavaScript's keyboard events. No keystroke data is ever transmitted to any server. Your key presses are only used to highlight the corresponding key on the visual layout and are never stored, logged, or transmitted outside your browser.

How is chatter detection different from the OS key repeat setting?

The OS key repeat fires a sequence of keydown events with e.repeat = true once you hold a key beyond the OS repeat delay. This tool ignores e.repeat events entirely. Chatter detection measures the gap between consecutive non-repeat keydowns of the same physical key. If a key produces multiple keydowns without e.repeat within the threshold window, it's flagged as switch chatter — a hardware issue. You can adjust the threshold slider from 10ms to 150ms to tune sensitivity.

What is 'break contact' and how does the tool detect it?

Break contact (also called 'chatter on release') is when a key switch briefly re-closes during release, causing a stray keydown event without a matching keyup. The tool detects this by tracking held keys: if a keydown arrives for a key that's already being held down without an intervening keyup, it's flagged as break contact and highlighted in purple on the keyboard.

What do the colors on the waveform strip mean?

The rainbow gradient inside the keyboard case visualizes key hold duration in real time. Hue starts at green (120°) and cycles every ~1.5 seconds to red, purple, blue, and back to green. When you release all keys, the waveform resets — a visible gap in the rainbow confirms clean break contact.

What are 'Other Keys Detected' in the green badges?

These are keys that exist on your keyboard but aren't part of the standard 104-key layout — typically media keys (volume, play/pause), brightness controls, calculator, browser shortcuts, and other OEM-specific keys. They appear as green 3D-styled badges and help you verify that these extra keys are functioning.

What does the Win/Mac layout toggle do?

It swaps the labels on three modifier keys: Win → ⌘ Cmd, Alt → ⌥ Opt, Ctrl → ⌃ Ctrl. This helps Mac users who connect a PC keyboard visually match the legends on their keys. It does not remap the physical layout or change key positions — only the displayed labels change.

Does the typing test track my input or store passages?

No. The typing test runs entirely in your browser — your typed text, WPM, and accuracy calculations stay in memory until you refresh or leave the page. Uploaded .txt files are read via FileReader and are never sent to a server. The built-in passage library consists of public-domain texts and original content.

Does this work with mechanical keyboards, gaming keyboards, and laptops?

Yes. This tester works with any keyboard your operating system recognizes, including mechanical keyboards, membrane keyboards, gaming keyboards with macro keys, laptop built-in keyboards, and wireless Bluetooth keyboards. As long as the OS delivers keyboard events to the browser, the tester will detect them.

Keyboard Tester — Detect Chatter, Dead Keys & Test NKRO Free

Press 2+ keys

Max NKRO

Threshold50ms

Layout

Win

Mac

Esc

F10

F11

F12

PrtSc

ScrLk

Pause

Backspace

Ins

Home

PgUp

Num

Tab

[

]

Del

End

PgDn

Caps

;

Enter

Shift

↑

Enter

Ctrl

Win

Alt

Win

Ctrl

←

↓

→

Num

Caps

Scroll

Not tested

Pressed

Tested

Chatter

Break

Typing Test

Key History

Press any key to begin

Keyboard Tester — Detect Chatter, Dead Keys & Test NKRO Free

Free online keyboard tester. Detect dead keys, check N-key rollover (NKRO), identify chatter and break contact, visualize key hold duration, test typing speed, and discover extra media keys. Real-time chord display with adjustable threshold. Works with mechanical, gaming, laptop, and wireless keyboards. 100% private, no download needed.

Features

✓Real-time NKRO tracking — see exactly how many keys are pressed simultaneously with live chord/combo display and max NKRO counter

✓Chatter detection with adjustable threshold — distinguish OS key repeat from switch bounce via configurable gap timing

✓Break contact detection — identify intermittent key contact that triggers stray keydown events without a corresponding keyup

✓Long-press waveform visualization — rainbow gradient strip inside the keyboard case shows hold duration at ~60fps

✓Extra keys detection — media and special keys (volume, brightness, etc.) appear as green keycap-style badges

✓Win/Mac layout toggle — swaps Win/Alt/Ctrl labels between PC and Mac conventions without changing key positions

✓Typing test with Free and Words modes — custom text or file upload support, character-level accuracy, WPM tracking

✓Detailed key event log — unified scrollable panel with millisecond timestamps, event type, hold duration, and anomaly labels

How to Use

1Click anywhere on the page to focus the tester, then press any physical key — the keyboard lights up in real time.

2Watch the NKRO card at the top: the big blue number shows how many keys are held; held key names replace the subtitle when 2+ are pressed simultaneously.

3Adjust the chatter threshold slider to set the gap threshold (10–150ms) — consecutive keydowns of the same key within this window are flagged as chatter (orange).

4Toggle between Win and Mac layout via the toggle — this swaps the labels on Win, Alt, and Ctrl keys for Mac users.

5Scroll to the Typing Test section and choose Free mode for open-ended typing or Words mode for passage-based accuracy practice with custom text or .txt upload.

6Use Reset to clear all pressed states, history, and stats — useful when switching to a different keyboard or starting a fresh test session.

Frequently Asked Questions

Key History

Keyboard Tester — Detect Chatter, Dead Keys & Test NKRO Free

Features

How to Use

Frequently Asked Questions

Is this keyboard tester safe to use? Does it log my keystrokes?

How is chatter detection different from the OS key repeat setting?

What is 'break contact' and how does the tool detect it?

What do the colors on the waveform strip mean?

What are 'Other Keys Detected' in the green badges?

What does the Win/Mac layout toggle do?

Does the typing test track my input or store passages?

Does this work with mechanical keyboards, gaming keyboards, and laptops?

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