Keyboard chatter test. One press, typed twice.
A worn or dirty switch bounces: you press once and the keyboard reports a release and a second press a few milliseconds later. Type normally, or tap a suspect key a few dozen times, and the test counts every second press that arrives too soon after a release, per key, with the closest gap it saw. It runs inside the full keyboard test, so dead keys, stuck keys and rollover are read in the same pass.
One check
- Keyboard
One check after another, with your progress along the top and a plain verdict on each. Nothing you show the camera or say into the microphone leaves this page.
What it measures
Measured here, not assumed.
- Chatter per key
- A second keydown of the same key within 30 ms of its keyup. 30 ms is our line: a deliberate double tap takes well over that, so anything inside it is the switch.
- The closest gap
- The shortest release-to-press gap counted for each key. A few milliseconds is a clear bounce; near the line is a switch starting to wear.
- Auto-repeat left out
- Holding a key makes the system repeat it. The browser marks those presses as repeats, and they are never counted as chatter.
If it fails
The usual failures, and what fixes each.
- One key chatters
- Pull the keycap and blow out the switch; dust and crumbs are the usual cause. On a hot-swap mechanical keyboard, swap the switch.
- Several keys chatter
- Update the keyboard's firmware, where the maker offers one, and raise its debounce setting if it has one. A chatter-blocker utility filters it in software as a stop-gap.
- It types twice only sometimes
- Tap the key slowly fifty times here. An intermittent bounce shows within a few dozen presses; if none show, the problem is elsewhere, often a key repeat delay set very short.
Where a browser stops
What it cannot tell you.
- A bounce the keyboard's own firmware filters never reaches the browser, which is the point of that filter.
- The 30 ms line is ours. Chatter-blocker utilities let you set your own window, so there is no single published figure.
- Which part is at fault: dust, a worn contact or a loose socket all look the same from a web page.
Privacy
Nothing leaves this page.
The camera and microphone are read on this page and stopped as soon as they have been measured. The clip you can play back lives in the browser's memory and is discarded when you leave. The location check discards the position. The internet test sends random bytes to this site and nothing else. The result is stored nowhere unless you ask for it by email, and then only the fact that an email was sent is kept.
Questions
Keyboard chatter test, answered
- What is keyboard chatter?
- A key that registers twice, or more, for one press. The switch's contacts bounce as they close, and the keyboard reports each bounce as a new press. It gets worse with wear and dirt.
- How is this different from key repeat?
- Key repeat is the system typing a held key again on purpose, after a delay. The browser marks those presses as repeats; this test leaves them out and counts only new presses that arrive too soon.
- Why 30 ms?
- It is our line. A person tapping one key as fast as they can is well slower than that, so a press inside it after a release is not a finger. Chatter-blocker tools let you choose your own threshold.
Read next