KEYBOARD CHATTER TEST

How to test keyboard chatter

1. Click ARM KEY SELECTION, then press the suspect key once.
2. Release it completely and continue tapping the same key at a normal, deliberate pace.
3. The key-selection press is ignored; after releasing it, run at least 25 deliberate down/up presses.
4. The page ignores keydown events marked by the browser as normal held-key auto-repeat.
5. It separately flags a second non-repeat keydown that arrives before release, plus very short release-to-next-keydown gaps.
6. Reset and repeat before concluding there is a switch problem.

Why release-to-next-keydown timing matters

For each complete press, the browser normally sees one non-repeat keydown followed by one keyup. A second non-repeat keydown before that keyup is suspicious because it is neither a clean new press nor normal repeat=true auto-repeat. A new non-repeat keydown arriving only a few milliseconds after release is a second pattern worth retesting.

A repeatable comparison workflow

1. Use a normal letter, number, or punctuation key and leave the threshold at 15 ms for the first run.
2. Make at least 25 complete, deliberate taps. Avoid typing words or deliberately double-tapping.
3. Record the completed presses, suspected duplicates, in-press duplicates, and shortest release gap.
4. Reset and repeat two more times with the same rhythm and connection.
5. Reset again, select a known-good key, and repeat with the same threshold and sample size.

A problem is more credible when the suspect key repeatedly produces multiple flags while the comparison key does not. One isolated flag is a reason to retest, not a component diagnosis.

Held-key repeat is not chatter

Operating systems intentionally generate repeated keydown events when a key is held long enough. Modern browsers mark those events with KeyboardEvent.repeat. GearCheck Lab counts them separately and excludes them from suspected-chatter timing.

Why the threshold is adjustable

There is no universal browser-visible millisecond threshold that proves a bad switch. The default is intentionally conservative at 15 ms. Lower thresholds reduce false flags from fast tapping; higher thresholds are more sensitive but can classify a genuine second press as suspicious.

Troubleshoot a suspicious result

• Only one key flags: clean around the switch if the keyboard maker permits it, compare that key on another device, and check warranty guidance.
• Many keys flag: check remapping or macro software, firmware settings, wireless interference, and the keyboard connection.
• Flags appear only in one browser: retry in another current browser with extensions disabled where practical.
• No events appear: click ARM KEY SELECTION again and use an ordinary key; the browser or operating system may reserve shortcuts and function keys.
• The symptom is intermittent: repeat several equal-size samples instead of increasing the threshold until a flag appears.

What this browser test can and cannot prove

The page observes browser-delivered keydown and keyup timing. It cannot inspect switch contacts, keyboard scan matrices, firmware debounce, USB packets, or operating-system input before the browser receives it.

A result can support troubleshooting, but it cannot certify a keyboard, identify a failed component, or guarantee that another game or application will see identical events.

Other causes of double typing

• Keyboard firmware or debounce configuration.
• Macros, remapping software, or accessibility tools.
• Wireless interference, a hub, cable, or unusual driver behavior.
• Application-specific key handling.
• A worn, dirty, or failing physical switch.

Keys the browser can intercept

Browser and operating-system shortcuts, function keys, Tab, Meta or Windows keys, and system combinations can be intercepted before this page sees them. For a clean test, use a normal letter, number, or punctuation key where possible.