About

This utility is engineered for mechanical keyboard enthusiasts, developers, and hardware technicians who demand precision in input diagnostics. Unlike generic text-based testers, this tool bypasses standard input processing to capture raw `ScanCode` and `KeyCode` events directly from the DOM Level 3 Events API. This allows for the detection of hardware-level faults such as switch chatter (unintended double actuation), ghosting (signal failure in the matrix), and NKRO (N-Key Rollover) limitations.

We have integrated a heuristic algorithm to measure the delta between key events. If a switch registers two `keydown` events within a window of 20 ms, it is flagged as "Chattering" - a common failure mode in oxidizing metal contacts. Additionally, the tool includes a massive database of mechanical switch specifications, allowing users to compare actuation forces and travel distances for over 60 industry-standard switches.

Formulas

To detect potential switch failure, we monitor the Inter-Key Latency (t_Δ). Mechanical switches require a physical debounce time. If a signal repeats faster than the physical limit of the leaf spring, it indicates electrical chatter.

t_Δ = t_n − t_n-1

Condition for Chatter Failure:

{

FAIL if t_Δ < 15msPASS otherwise

We also estimate the Effective Polling Rate (R) based on the minimum observed delta between distinct key events:

R ≈ 1000min(t_Δ) Hz

Reference Data

Manufacturer	Switch Model	Type	Actuation cN	Bottom Out cN	Pre-Travel mm	Total Travel mm
Cherry	MX Red	Linear	45	60	2.0	4.0
Cherry	MX Blue	Clicky	60	60	2.2	4.0
Cherry	MX Brown	Tactile	55	60	2.0	4.0
Cherry	MX Black	Linear	60	80	2.0	4.0
Cherry	MX Speed Silver	Linear	45	70	1.2	3.4
Gateron	Yellow (KS-3)	Linear	50	65	2.0	4.0
Gateron	Ink Black V2	Linear	60	70	2.0	4.0
Gateron	Blue	Clicky	60	55	2.3	4.0
Kailh	Box White	Clicky	50	60	1.8	3.6
Kailh	Box Jade	Clicky	50	65	1.8	3.6
Kailh	Box Navy	Clicky	60	90	1.8	3.6
ZealPC	Zealio V2 67g	Tactile	67	67	2.0	4.0
ZealPC	Tealio V2	Linear	67	67	2.0	4.0
Topre	Electro-Capacitive	Tactile	45	45	2.0	4.0
Drop	Holy Panda	Tactile	67	67	2.0	4.0
NovelKeys	Cream	Linear	55	70	2.0	4.0

Frequently Asked Questions

NKRO is a feature where every key press is registered individually, even if all keys are pressed simultaneously. Standard keyboards often have 6-key rollover (6KRO), meaning if you press 7 keys, one will be ignored. This tool visualizes exactly how many simultaneous inputs your device supports.

The "Fn" key is processed internally by the keyboard's microcontroller (firmware level) to trigger layers or macros. It typically does not send a scan code to the Operating System, so the browser cannot detect it.

Chatter happens when a switch sends multiple signals for a single press. This is usually caused by dust, oxidation, or a failing leaf spring. If this tool flags a key as "Chatter" red, try cleaning the switch with compressed air or contact cleaner.

Text editors handle "repeated characters" (holding a key down) differently than raw signal events. This tool visualizes the raw "keydown" and "keyup" events, allowing you to diagnose issues with the switch mechanism itself, independent of your OS repeat rate settings.

It is an approximation. Browsers run in a sandboxed environment and cannot access the USB driver directly. However, by measuring the timing between high-speed inputs, we can infer if the keyboard is updating at 125Hz, 500Hz, or 1000Hz.