Keyboard Double-Click Test
Find out if a key registers twice from one press.
How it works
- 01
Pick the key you suspect, then press it slowly and deliberately — roughly once a second. Do not hold it down.
- 02
Operating system auto-repeat is filtered out, so a held key will not be mistaken for chatter.
- 03
An interval under 70ms means the switch bounced. That is chatter: one physical press producing two signals.
- 04
Chatter usually affects one specific key rather than the whole board, which is why the test targets a single key at a time.
Common questions
What is keyboard chatter?
A single keypress registering two or more times. The switch contact bounces as it closes, and worn or dirty switches bounce long enough for the firmware to read it as separate presses.
How do I fix a chattering key?
Compressed air or contact cleaner clears debris and often solves it. Some keyboards let you raise the debounce time in firmware. On a hot-swap board, swapping the switch takes seconds.
Why does the test ignore held keys?
Holding a key makes the operating system fire repeats on purpose. Counting those would flag every keyboard as faulty.